What happens to the the eardrum, a thin membrane at the end of the ear canal, when it is struck by a sound wave? a) It vibrates.
b) It closes.
c) It rotates.
d) It inverts.

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.