If Actus non facit reum nisi mens sit rea is a cardinal principle of criminal law, then which one of the following statements correctly, reflects the above principle?

A. Mens rea is an essential element of a crime and there cannot be a  crime without mens rea

B. Criminal liability under Indian Law always implies mens rea

C. To constitute a crime there must be actus reus and mens rea

D. Actus reus is not always necessary to constitute a crime