Question

what are hormones?
○ glands
○ cells
○ chemical messengers
○ building blocks of proteins

Explanation:

Hormones are defined as chemical messengers that are secreted by glands and travel in the bloodstream to regulate various physiological processes. Glands are the organs that secrete hormones, cells are the basic units of life, and building blocks of proteins are amino acids. So the correct option is the one with "chemical messengers".

Answer:

C. chemical messengers (assuming the options are labeled A: glands, B: cells, C: chemical messengers, D: building blocks of proteins; if the original labels are different, adjust the identifier but keep the text "chemical messengers")