It is false that no high schools are institutions plagued by drunkenness. Therefore, it is false that some high schools are not institutions plagued by drunkenness.
A) Invalid, illicit subalternation.
B) Invalid, illicit subcontrary.
C) Invalid, illicit contrary.
D) Invalid, illicit conversion.
E) Valid.

Question

Quizplus · Accepted Answer

The argument commits the fallacy of illicit subalternation, which occurs when a conclusion about a particular claim (some) is improperly drawn from a universal claim (all or no) without proper logical basis. The original statement negates a universal negative ("no high schools are institutions plagued by drunkenness"), but the conclusion improperly attempts to negate a particular negative ("some high schools are not institutions plagued by drunkenness") without valid logical support.

It Is False That No High Schools Are Institutions Plagued