Crunches are principally a(n) exercise. a. abdominal
b. arm
c. back
d. chest

Its an abdominal exercise

Explanation:

The crunch is a classic core exercise. It specifically trains your abdominal muscles, which are part of your core

answer: my answer would be a) scheduling workouts with your friend for consistent days and time

explanation:

for me personally i would be much more likely to go to the gym with a friend because i wouldn't want to cancel on them or stand them up.