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". 

. four bikers at the start of the line <sep> (A) get no a jump. (B) are wearing different colors of uniforms and helmets, they are about to get start the race. (C) leave and race towards a parking lot on the right. (D) go on the parallel bars but they can't take off their bikes.
B

[header] How to clean rubber boots [title] Wipe away light dirt and grime. [step] If your boots aren't especially dirty, you can usually clean them easily with a damp cloth. To prevent dirtiness from building up on your boots and causing longer cleaning times, do this after each time you use your boots. <sep> (A) Before handling an object or stepping on something wet, make sure you wipe it away on a rag first. Use a mild soap and water to wipe off even the smallest traces of dirt. (B) [substeps] To increase the dirt fighting potential of your damp cloth, mix 1 tsp (5 ml) of dish soap with a ¼ gallon (1 l) of water. Douse your rag in this, and wipe down the boots. (C) [title] Grind three pounds (177 g) of dry powder on a coffee grinder. [step] The dry powder will help to transfer dirt and dust to the boots. (D) This will clear little dirt and grime off of your boots, leaving them looking brand new. [substeps] If your boots are already cleaned, you may need to consult a shoe store or partner to inspect them for a better cleaner.
B

Many people are on a beach. A man starts doing flips into the water. he <sep> (A) is snowboarding. (B) approaches a dog. (C) does it many different times. (D) then runs up several more ramps.

C