In Familial hypercholesterolemia there is deficiency of: (A) LDL receptor, (B) Apoprotein A, (C) Apo protein C, (D) Lipoprotein lipase
Answer is A. LDL receptors 

Familial hypercholesterolemia (type IIa) is due to deficiency of functional LDL receptors as a result of different types of mutations.