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

Brief Explanations:

To determine the correct answer, we analyze each option:

• Glands are organs that secrete hormones, not the hormones themselves.
• Cells are the basic units of life; hormones are not cells.
• Hormones are defined as chemical messengers that regulate physiological processes in the body.
• Building blocks of proteins are amino acids, not hormones.

Answer:

C. chemical messengers