The correct option is C (B) & (C) above
Section 29 of the Indian Contract Act, 1872 lays down that the agreements in which the meaning of the terms are not certain and also not capable of being made certain, are void. But illustration to this provision states that in the given case where goods are being sold by the dealer of oil, it can be said fro certain that a dealer intends to sell certain quantity of oil to his customer. Therefore, the nature of trade is indicative of a valid contract.