Identify the sentence that incorporates parallel structure.
 A) My week at camp included rock-climbing, mountain biking and sleep. 
 B) During my week at camp, I swam, hiked, biked and skiing on the lake. 
 C) My week at camp consisted of playing soccer, riding mountain bikes and crafts. 
 D) During my week at camp, I scaled the climbing wall, built a fort, and jumped on the trampoline. 
 Elim