Title: Foreign exchange option
Content:  In finance, a foreign exchange option (commonly shortened to just FX option or currency option) is a derivative financial instrument that gives the right but not the obligation to exchange money denominated in one currency into another currency at a pre-agreed exchange rate on a specified date. See Foreign exchange derivative. The foreign exchange options market is the deepest, largest and most liquid market for options of any kind. Most trading is over the counter (OTC) and is lightly regulated, but a fraction is traded on exchanges like the International Securities Exchange, Philadelphia Stock Exchange, or the Chicago Mercantile Exchange for options on futures contracts. The global market for exchange-traded currency options was notionally valued by the Bank for International Settlements at $158.3 trillion in 2005.
Title: Foreign exchange option
Content: Call option – the right to buy an asset at a fixed date and price. ; Put option – the right to sell an asset at a fixed date and price. ; Foreign exchange option – the right to sell money in one currency and buy money in another currency at a fixed date and rate. ; Strike price – the asset price at which the investor can exercise an option. ; Spot price – the price of the asset at the time of the trade. ; Forward price – the price of the asset for delivery at a future time. ; Notional – the amount of each currency that the option allows the investor 
Title: Foreign exchange market
Content:  A foreign exchange option (commonly shortened to just FX option) is a derivative where the owner has the right but not the obligation to exchange money denominated in one currency into another currency at a pre-agreed exchange rate on a specified date. The FX options market is the deepest, largest and most liquid market for options of any kind in the world.
Title: Foreign exchange option
Content:  The difference between FX options and traditional options is that in the latter case the trade is to give an amount of money and receive the right to buy or sell a commodity, stock or other non-money asset. In FX options, the asset in question is also money, denominated in another currency. For example, a call option on oil allows the investor to buy oil at a given price and date. The investor on the other side of the trade is in effect selling a put option on the currency. To eliminate residual risk, traders match the foreign currency notionals, not the local currency notionals, else the foreign currencies received and delivered do not offset. In the case of an FX option on a rate, as in the above example, an option on GBPUSD gives a USD value that is linear in GBPUSD using USD as the numéraire (a move from 2.0000 to 1.9000 yields a .10 * $2,000,000 / $2.0000 = $100,000 profit), but has a non-linear GBP value. Conversely, the GBP value is linear in the USDGBP rate, while the USD value is non-linear. This is because inverting a rate has the effect of, which is non-linear.
Title: Foreign exchange option
Content:  For example, a GBPUSD contract could give the owner the right to sell £1,000,000 and buy $2,000,000 on December 31. In this case the pre-agreed exchange rate, or strike price, is 2.0000 USD per GBP (or GBP/USD 2.00 as it is typically quoted) and the notional amounts (notionals) are £1,000,000 and $2,000,000. This type of contract is both a call on dollars and a put on sterling, and is typically called a GBPUSD put, as it is a put on the exchange rate; although it could equally be called a USDGBP call. If the rate is lower than 2.0000 on December 31 (say 1.9000), meaning that the dollar is stronger and the pound is weaker, then the option is exercised, allowing the owner to sell GBP at 2.0000 and immediately buy it back in the spot market at 1.9000, making a profit of (2.0000 GBPUSD − 1.9000 GBPUSD) × 1,000,000 GBP = 100,000 USD in the process. If instead they take the profit in GBP (by selling the USD on the spot market) this amounts to 100,000 / 1.9000 = 52,632 GBP.
Title: Foreign exchange risk
Content:  forward contracts. If a company decides to purchase an option, it is able to set a rate that is "at-worst" for the transaction. If the option expires and it's out-of-the-money, the company is able to execute the transaction in the open market at a favorable rate. If a company decides to take out a forward contract, it will set a specific currency rate for a set date in the future. Currency invoicing refers to the practice of invoicing transactions in the currency that benefits the firm. It is important to note that this does not necessarily eliminate foreign exchange risk, but rather moves its burden from one party to 
Title: Option (finance)
Content:  In finance, an option is a contract which conveys to its owner, the holder, the right, but not the obligation, to buy or sell an underlying asset or instrument at a specified strike price on or before a specified date, depending on the style of the option. Options are typically acquired by purchase, as a form of compensation, or as part of a complex financial transaction. Thus, they are also a form of asset and have a valuation that may depend on a complex relationship between underlying asset value, time until expiration, market volatility, and other factors. Options may be traded between private parties in over-the-counter (OTC) transactions, or they may be exchange-traded in live, orderly markets in the form of standardized contracts.
Title: Foreign exchange option
Content:  against the US$, then the UK firm receives more GBP. This uncertainty exposes the firm to FX risk. Assuming that the cash flow is certain, the firm can enter into a forward contract to deliver the US$100,000 in 90 days time, in exchange for GBP at the current forward rate. This forward contract is free, and, presuming the expected cash arrives, exactly matches the firm's exposure, perfectly hedging their FX risk. If the cash flow is uncertain, a forward FX contract exposes the firm to FX risk in the opposite direction, in the case that the expected USD cash is not received, typically making an option a better choice. Using options, the UK firm can purchase a GBP call/USD put option (the right to sell part or all of their expected income for pounds sterling at a predetermined rate), which:
Title: Foreign exchange derivative
Content:  【Foreign forward swap transaction trading】: The parties of a swap contract agree to periodically swap capital in some time. 【Foreign exchange option trading】: The contract can agree the option holder to exchange it at a defined price as his right instead of an obligation. 【Forward exchange futures transaction trading】: Future contract’s buyers or sellers submit margin at the beginning of trading, as a kind of buffering mechanism. The margin needs to make corresponding adjustment on time according to the price of contract. 【Forward forex exchange trading】: Similar to futures, but it is an unstandardized agreement without the margin requirement.(Lu Lei, 2008)
Title: Notional amount
Content:  In FX derivatives, such as forwards or options, there are two notionals. For example, if an individual has a call option on USD/JPY currency struck at 110, and one of these is purchased, then this gives the buyer the option to pay 100 USD and receive 110 × 100 = 11,000 JPY, so the USD notional is 100 USD, and the JPY notional is 11,000 JPY. Note that the ratio of notionals is exactly the strike, and thus if the strike is moved, one of the notionals will change. For instance, if the strike is moved to 100, and the USD fixed at 100, the JPY notional becomes 10,000; the buyer will pay the same number of USD and receive fewer JPY. Alternatively, JPY currency could be held constant at 11,000 and change the USD notional to 110: hence, the buyer will pay more in USD and receive the same number of JPY. When hedging foreign currency exposure, such as for an American business in USD, an outflow of 11,000 JPY, the foreign currency notional must be fixed.

Question: which foreign currency option is the​ right but not the​ obligation to buy foreign​ currency?
Answer: foreign exchange option.