______ is the most abundant protein in animal world and _____ is the most abundant protein in the whole biosphere.

Options

A. Collagen, RuBisCO
B. Collagen, keratin
C. Keratin, RuBisCO
D. Keratin, collagen

Answer

A

Explanation

Keratin is a fibrous protein which forms external protective structures of animals like nails, hoofs, scales, hair, feathers, horny layer of skin, ets.