Which of the following is a function of stomata?
release glucose
absorb sunlight
release water vapor
absorb water through the roots

The most accurate answer is release water vapor.

Stomata are special pores in plants  found typically on the outer leaf skin layer called the epidermis. They consist of two specialized cells called guard cells that surround a tiny pore called a stoma.

Their main function is to allow water vapor and gases such as carbon dioxide and oxygen to move rapidly in and out of the leaf.

The word stomata means mouth in Greek because they allow communication between the  internal and external environments of the plant.