mehaksal wrote:A valid argument is often defined as one in which it is not possible for all the premises to be true and the conclusion false. A circular argument is sometimes defined as one in which one of the premises is identical to the conclusion. From these definitions we can infer that...

(A) Every circular argument is valid as long as its premises are true.
(B) Every valid argument is circular.
(C) No circular argument is valid.
(D) Some circular arguments are valid, and some are not.
(E) Some circular arguments are not valid, and some valid arguments are not circular.

vk_vinayak wrote:

mehaksal wrote:A valid argument is often defined as one in which it is not possible for all the premises to be true and the conclusion false. A circular argument is sometimes defined as one in which one of the premises is identical to the conclusion. From these definitions we can infer that...

(A) Every circular argument is valid as long as its premises are true.
(B) Every valid argument is circular.
(C) No circular argument is valid.
(D) Some circular arguments are valid, and some are not.
(E) Some circular arguments are not valid, and some valid arguments are not circular.

I think A.

According to the stimulus, the definition of Valid sentence: if all premises are true, then conclusion is also true.
Since, in a circular argument conclusion is identical to a premise, it follows that if all premises are true, conclusion must be true. If premises are true and conclusion is also true, it's a valid argument. So, we can say that when all premises of a circular argument are true, it is a valid argument.