Given the task definition and input, reply with output. In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

As wolves need more energy to catch fast prey (A) their pulse will decrease (B) their shoes will wear out (C) their heart rates will go higher (D) they will start using vehicles to chase their prey
C