Collagen is a
a)	Phosphoprotein	b)	Globulin	c)	Derived protein	d)	Scleroprotein

(d)

Scleroproteins are the proteins of supportive tissue and occur in hard parts of animal body. These are insoluble in water, absolute alcohol, dilute acid or alkali or other neutral solvents. Examples of scleroproteins  are keratin, collagen, elastin, fibroin, chondrin, ossein, etc.