Matthew has a contract to sell a piece of real estate to Betty for $35,000. Matthew breaches the contract and decides to keep the property even though the market price is only $31,000. Betty can recover:
a. nothing, because Matthew wanted to keep his land.
b. $35,000 as the contract price on the land.
c. specific performance.
d. $4,000 as the difference between the market price and the contract price