You will be given a definition of a task first, then some input of the task.
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 build a dog agility course [title] Create some obstacles. [step] These are important for increasing your dog's agility and running skills. [title] Make weaves (a type of obstacle dogs weave through). <sep> (A) [step] You can make those from pvc pipes as well but they are more time consuming. [substeps] The best way to do this is to buy very large, tall orange cones, line them up in a line and have your dog weave through. (B) [title] Build a bridge if it is a simple obstacle course. [title] Build a new field of seeds if this is an obstacle course. (C) [step] Make them part of your training course. [title] Consider creating a class or two for your dog because you will want the academy to know you are training. (D) [step] Also remember that the energy generated by weaving and running around obstacles can send them flying. This step is necessary if you want to move your dog for mobility.
Output:
A