Venn diagrams in reasoning – UGC NET Question

A, B, C and E are correct descriptions of Venn-diagram use. D is wrong because syllogisms involve three terms (S, P, M) and commonly require a three-circle Venn diagram to test validity. Therefore D alone is wrong.

Option A:
Option A is correct because it isolates D as the sole error and keeps the standard Venn conventions in A–C and the exam-use point E.

Option B:
Option B is incorrect because it wrongly treats A as an error; A is a basic purpose of Venn diagrams.

Option C:
Option C is incorrect because it wrongly treats B as an error; shading does indicate emptiness.

Option D:
Option D is incorrect because it wrongly treats C as an error; “×” indicates existence.