Which statement best describes the molecular structure of protein, along with one of the functions of proteins?
it is a straight chain hydrocarbon that can fight disease.
it is a complex, folded chain that regulate cell processes.
it is a simple carbon, hydrogen, and oxygen molecule that creates movement.
it is a chain of nucleotides, and forms muscle, bone, and ligaments.

The second option is the best answer.

Proteins are complex polymers of amino acids. They are folded into 3 dimensional structures . This folding defines not only the size and shape of the protein, but also its function.

The folding of a protein allows for interactions between amino acids that may be distant from each other in the primary  sequence of the protein. In enzymes, some of these amino acids form a site in the structure that catalyzes the enzymatic reaction. This site is called the active site.

c should be the answer