Answer the following question given this paragraph: 

How Hormones Work Hormones cause changes in target cells by binding to specific cell-surface or intracellular hormone receptors, molecules embedded in the cell membrane or floating in the cytoplasm with a binding site that matches a binding site on the hormone molecule. In this way, even though hormones circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors. Receptors for a specific hormone may be found on or in many different cells or may be limited to a small number of specialized cells. For example, thyroid hormones act on many different tissue types, stimulating metabolic activity throughout the body. Cells can have many receptors for the.


Q: Although what biochemicals circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors?

 Choices:

- Cells

- organs

- enzymes

- hormones

A:
hormones
