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".

[EX Q]: [header] How to buy a last minute cheap flight [title] Check airline newsletters, websites that specialize in last minute air travel and the travel section of your local newspaper to find last minute deals on flights. [step] Sometimes you can save money by booking flights late because airlines that have not filled their planes will offer discount fares. [title] Compare airfares from different airlines, websites and travel agencies. <sep> (A) [step] Look at every airline's website so that you can compare and contrast prices. [title] Opt for free flights as before, otherwise follow the full booking program and you'll not miss your flight in a long time. (B) [step] Try booking flights from big-ticket airlines such as kiwi airlines and delta. [title] Compare prices from travel agencies that are offering cheaper flights. (C) [step] Purchasing flights directly from the airline is not always the cheapest deal, so check out a few different travel websites and travel agencies to compare prices. [title] Search for flights during undesirable days and times. (D) [step] Compare each airline's prices with the prices you are interested in. You might be able to find a cheaper flight for free.
[EX A]: C

[EX Q]: A man shows how to change a tube in a tire. he <sep> (A) puts a jack under the tube to lift it up. (B) puts a new tire on the tube. (C) takes the old tube out, puts the new one in, then pumps it up. (D) moves dirt covering the tube.
[EX A]: C

[EX Q]: [header] How to change engine oil and oil filter for perodua kancil 850 (new model ) [title] Before you start to service your car, prepare the tools and equipments such as a funnel, oil filter, spanner, wrench and genuine engine oil. [title] Park the vehicle on a level surface. [step] Warm up the engine to operating temperature and stop it. <sep> (A) Should it slow down (or try to slow down or fail to engage the gas before driving) you could right into the breakdown wall or something, ruining the vehicle. Find an empty road someplace that is free from lots of clutter. (B) [title] Lay used newspaper or old box below the drainage engine. [title] Place a container under the oil pan for draining engine oil. (C) Push the turn bar bar out to get started so that the new oil is running smoothly. Run some line on the outside of the inner tube with the old oil oil (i.e., let it cool). (D) Check on the oil and oil tube for any last minute changes before attempting to perform so as not to change the engine in an accident. [substeps] If you are performing this for a licensed vehicle, follow the command you entered in the owner's manual.
[EX A]:
B