Steroids are a major class of. a Lipids
b Proteins
c Vitamins
d None of the above

D

Explanation:

Additional classes of steroids include:  

Neurosteroids such as DHEA and allopregnanolone

Aminosteroid neuromuscular blocking agents such as pancuronium bromide

answer; i believe is(b)converging

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme