If very loud sound is produced, we immediately cover our ears with hands. What type of response is this?

it is known to be a reflex action called acoustic stapedius reflex or ASR

Explanation:

Loud noise can damage cells and membrane in the cochlea. Listening to loud noise for a long time can over work hair cells in the ear which can cause these cells to die.

Harmful effect might continue even after noise exposure has stopped.

ASR is a reflex in which the stapedius muscle contracts involuntarily within one-tenth of ascend in response to noise...

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.

thinking it would be d not too sure but i think it's right