D Offers to Sell a Painting to V

D offers to sell a painting to V. Thinking it is an original, V offers £3000 which D accepts. In fact, it is only a limited edition print worth £75. D is aware of V's mistake but keeps silent. Which of the following represents the law:

A) D commits theft when he appropriates the money with a dishonest intention despite the contract being valid under civil law.
B) D commits theft when he appropriates the money with a dishonest intention because the contract under civil law is void.
C) D does not commit theft because V should have inspected the painting more carefully.
D) D does commit theft because his conduct is immoral.