2) b is correct
Melanin in the Skin. Melanin is the main pigment in skin, where it's made by cells called melanocytes. ... Blood vessels in the skin also contribute to skin color due to the presence of hemoglobin, a red pigment in blood. Melanin is deposited near the surface of the skin.
Tyrosine is a non-essential amino acid. In animals it is synthesized fromPHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; andmelanin. Tyrosine is an essential amino acidthat readily passes the blood-brain barrier.