Question

select the best evidence to support the statement that crying can protect your eyes.
dust and dirt can make your eyes itchy and damage the delicate surfaces. eyelashes act as filters, keeping many particles away from the surface of the eyes. tears wash over the eyes to clean them. tears also contain an enzyme, called lysozyme, that destroys bacteria.
saliva in your mouth washes over your teeth to clean them. it also prevents microbes from growing inside your mouth.
your stomach can usually deal effectively with any microbes that enter it. the digestive juices inside your stomach are extremely acidic, and will kill most microbes. if toxins enter the stomach, you may vomit to expel them from your body. toxins and microbes that get past your stomach defenses travel on through your digestive system.
from carol ballard, the immune system. copyright 2003, 2009 by heinemann library

Explanation:

To support "crying can protect your eyes", we need evidence about tears/eyes. The first paragraph says "Tears wash over the eyes to clean them. Tears also contain an enzyme, called lysozyme, that destroys bacteria." This directly relates to how tears (from crying) clean and protect eyes. The other paragraphs are about saliva (mouth) and stomach, not eyes.

Answer:

Tears wash over the eyes to clean them. Tears also contain an enzyme, called lysozyme, that destroys bacteria.