Given the task definition and input, reply with output. In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".

[header] How to buy gas gift cards [title] Choose your retailer. [step] Almost every major gas station offers gift cards. To decide which station's card you want to buy, ensure that the person you're buying the card for has a gas station of the corresponding card nearby. <sep> (A) If you're buying a pass card, check the pass card they've placed online if they don't already have one. It's worth the extra effort to see what happens when you get the card on the bus, train, or boat. (B) The point at which you can find the location of a gas station is to determine the best location for the card. Many such stations allow a gas station to run at a four-day minimum. (C) For instance, if you buy the card for your son who moved away, you might not know what gas stations he has nearby. Use an online map system like mapquest to look up gas stations near him. (D) Always confirm the retailer's card stock number (apn) and the card's full date (road date) of purchase. [substeps] Most gas stations offer gift cards for both street and road locations; however, even one vendor deals on both ground and road locations.
C