Biology

The correct answer is C.protein.

Proteins are the building blocks of the body and are essential for the structure, function, and regulation of tissues and organs. They are involved in the formation of hair, muscles, and many other tissues, as well as enzymes, hormones, and antibodies.

Here’s a breakdown of the other options:

A.Nucleic Acids: These include DNA and RNA, which are responsible for storing and transmitting genetic information, but they don't directly build tissues like proteins do.

B.Lipids: Lipids are involved in energy storage, cell membrane...