It is false that some flu shots are guarantees of immunity. Therefore, some flu shots are not guarantees of immunity.
A) Invalid, illicit contrary.
B) Invalid, illicit subalternation.
C) Valid.
D) Invalid, illicit subcontrary.
E) Invalid, illicit contraposition.

Question

Quizplus · Accepted Answer

This is a valid statement as it follows the rule of denying the predicate. The original statement states that "some flu shots are guarantees of immunity" which means that there are flu shots that provide immunity, but not all of them do. By denying the predicate, the statement "some flu shots are not guarantees of immunity" is logically true as it allows for the possibility that some flu shots may not provide immunity.

It Is False That Some Flu Shots Are Guarantees of Immunity