B, a man of unsound mind, sets fire to a dwelling house on A's instigation. Here, B is exempted from criminal liability (Section 84, Indian Penal Code), but A is guilty of abetting mischief by fire with intent to destroy the house. The principle for this criminal liability may be explained by which one of the following explanations?

A. The abetment of an offence being an offence, the abetment of such an abetment is also an offence

B. The person who has been instigated to commit an offence may not be liable under criminal law for his act because of his being of unsound mind at the time of committing the offence but the abetment to commit mischief by fire being an offence, abetment of such offence incurs liability

C. To constitute offence of abetment it is not necessary that the act abetted should be committed

D. It is not necessary to the commission of the offence by conspiracy that the abettor should work in concert with the person who commits it

Answer: Option B