Grover Contracts to Sell Two Tracts of Land to Hank

Multiple Choice

Grover contracts to sell two tracts of land to Hank. Both parties believe that the two tracts are adjacent, but in fact they are not. Grover is still willing to sell the land, but under these circumstances the deal would adversely affect Hank.
-Refer to Fact Pattern 13-2.Because of the parties' belief about the adjacency of the property,their contract is

A) unavoidable.
B) unconscionable.
C) unenforceable.
D) voidable.