Final answer:
Both the buyer and the seller have the right to sue for specific performance.
Step-by-step explanation:
In a contract for the sale of land, both the buyer and the seller have the right to sue for specific performance when the other party defaults.
Specific performance is a legal remedy that requires a party to fulfill their contractual obligations as agreed upon in the contract. In the context of a land sale contract, this would mean that if one party defaults on their obligations, the other party can seek a court order to compel them to complete the sale.