Answer:
(d). Sending signals across the organism
Explanation:
Proteins are one of the most important biomolecules that play different roles in organisms. Proteins are made up of polymerization of amino acids. There are some protein molecules that act as signaling molecules that transfer signals from one cell to another.
Insulin hormone, cytokines, and some other peptide hormones are examples of protein molecules that send signals across the organisms.
Thus, the correct answer is option). d.
