Which best supports the claim that the argument in the last three sentences of paragraph one is valid?

which best supports the claim that the argument in the last three sentences of paragraph one is valid?
a) it is possible for both its premises to be true and its conclusion to be false.
b) the premise can be determined to be true and the conclusion follows that premise.
c) some support for the valid conclusion must exist to demonstrate its truth.
d) this argument is valid because it leads to its own conclusion.