A contracts with B to grow a crop of indigo on A's land and to deliver it to B at a fixed rate and C guarantee A's performance of this contract. B diverts a stream of water which is necessary for irrigation of A's land and thereby prevents him from raising the indigo.

A. A is liable on his guarantee

B. A is partly liable on his guarantee

C. A is no longer liable on his guarantee

D. None of the above

Answer: Option C