Final answer:
The intent of the parties is fundamental to a contract, which makes that statement true. The necessary and proper clause has expanded, not limited, the power of the national government, so that statement is false. The Constitutional Convention was for revising the Articles of Confederation, true, but it resulted in a new Constitution.
Step-by-step explanation:
The intent of the parties is indeed a central element of a contract. When it comes to contracts, the agreeance of the parties involved on the terms and conditions is essential. This mutual agreement or intent is what makes the contract valid and binding for all parties involved. Therefore, the statement 'The intent of the parties is a central element of a contract' is true.
Regarding U.S. constitutional history, the necessary and proper clause has actually served to expand the powers of the national government rather than limit it. This clause gives Congress the flexibility to pass laws deemed necessary and proper for carrying out its powers. Hence, the statement 'The necessary and proper clause has had the effect of limiting the power of the national government' is false.
The Constitutional Convention that occurred in 1787 was indeed for the purpose of revising the Articles of Confederation. But rather than merely revising, the convention resulted in the creation of a completely new document, the U.S. Constitution. So the statement 'The Constitutional Convention met in 1787 for the purpose of revising the Articles of Confederation' can be considered true, albeit the outcome was more than just revision.