Which two of the following propositions cannot both be false, though both of them may be true? Choose the correct answer from the options given below.

The pair that cannot both be false yet may both be true is "Some cows are vegetarians" and "Some cows are not vegetarians".

Statement 3 is the particular affirmative I and Statement 4 is the particular negative O.

I and O are subcontraries on the square of opposition.

Subcontraries cannot both be false at once, so at least one must be true.

They may, however, both be true together, unlike contraries.

This trait of never both-false but possibly both-true marks Statements 3 and 4 as subcontraries.