Of two sub-contraries, if one is false, the other is necessarily

ATrue ✓ Correct

BFalse

CDoubtful

DNeither true nor false

Correct answer: (A) True

Explanation

Of two sub-contraries, if one is false, the other is necessarily true.

Sub-contraries cannot both be false at the same time.

So falsity of one forces the truth of the other.

If "Some S are P" is false, "Some S are not P" must be true.

The law of sub-contraries guarantees the second as true here.

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