Teacher: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".
Teacher: Now, understand the problem? Solve this instance: A woman in an orange shirt is sitting on an exercise machine. she <sep> (A) gets on the machine and starts riding it. (B) engages in some form of mount. (C) begins working out on the exercise machine. (D) is using a dodgeball machine.
Student:
C