What can you do to reduce muscle tension as a result of too much stress?

The skin includes multiples layers. which of the following is not one of the layers of the skin?

Lina went camping in the woods. while camping, she accidentally touched a strange plant. her hand immediately started itching, and her skin erupted in hives. after she got home, her grandmother cooked some oatmeal, wrapped it in a cloth, and put it on lina’s affected hand. lina’s grandmother followed a traditional remedy.

What is the function of the retina?