Concept:A legally binding and enforceable agreement is known as a contract.
Explanation:An agreement arises when two or more parties reach a mutual understanding.
However, not every agreement can be enforced by law.
For an agreement to be enforceable, it must contain essential elements.
These elements include offer, acceptance, consideration, capacity, and lawful purpose.
When all these conditions are satisfied, the law requires the parties to fulfil their obligations.
This type of legally binding agreement is called a contract.
An offer is only one part of forming a contract, not the final enforceable agreement.
A decree is an official court order or judgment.
A declaration is simply a formal statement, which may lack legal enforceability.
Thus, the correct description of an enforceable agreement is a contract.
Answer:C. A contract