Read the following context and choose the best option to answer the question.
Context: There was a new instructor there today . Normally I ' m hesitant about new instructors because I do n't think they are as tough ( I like a challenge ) , but this girl was tough and she was preggo too ( only a couple of months , though ) . After Jazzercise we came straight home so Bradley could eat lunch and I could prepare a snack for his preschool class .
Question: Why did the narrator feel the workout was worthwhile ?
Options: 
A. The new instructor was easy .
B. None of the above choices .
C. The new instructor was very diligent .
D. The new instructor was very light on demands .


C