7. which one of the following muscle actions would not be classified as an isotonic contraction? (1 point)
a tying your shoe
b lifting a glass of water to your mouth
c pushing against a stationary wall
d writing a letter

Agroup of engineering students from purdue university reported that its licking machine, modeled after a human tongue, took an average of 364 licks to get to the center of a tootsie pop. twenty of the group's volunteers assumed the licking challenge-unassisted by machinery-and averaged 252 licks each to the center.

I don’t know sorry I need p o i n t s