Darell has a home gym that his older brother set up. Nobody has used the gym for a few years but Darell has decided to give weight lifting a try. He talks to his gym teacher, who shows him proper form for the exercises and does performance testing. Together they design a starter program that includes a warm-up, stretching, and some basic weight-lifting exercises, followed by a time of stretching. On the first day of his routine, Darell is injured. What is the most likely cause of his injury? A. Darell is experiencing what can happen when you overtrain. B. Darell is experiencing what can happen when you don't know how to do the exercises. C. Darell is experiencing what can happen when you don't properly plan a workout. D. Darell most likely did not check the gym equipment for safety issues before he used it.