Which of the following is a correct pair of masculine and feminine gender?

Nephew:Niece

The correct answer is Nephew:Niece. The other options are not correct pairs of masculine and feminine gender.

• Boar:Boaress is a correct pair, but boar and boaress are both nouns referring to female boars.
• Bachelor:Bachelor is not a correct pair because bachelor is already a gender-neutral term.
• Chairman:Chairwomen is not a correct pair because the feminine form of chairman is chairwoman.