The Catholic Philosopher Saint Thomas Aquinas Offered the Following Argument

Multiple Choice

The Catholic philosopher Saint Thomas Aquinas offered the following argument for God's existence: Some things have causes. Since nothing can cause itself, each thing that has a cause must be caused by something else. But if everything had a cause, then the chain of causes would go on forever. It is impossible for the chain of causes to go on forever. Therefore, there must be something that can cause other things but is not caused by anything else. That uncaused cause is God. In this argument, the claim that "it is impossible for the chain of causes to go on forever" is:

A) Background information.
B) One of the argument's premises.
C) A subconclusion of the argument.
D) The argument's conclusion.