Explanation:

The noun "nun" refers to a woman who has taken vows to live a religious life, typically within a convent or monastery. The masculine gender for the noun "nun" is "monk".

Reasoning:

To determine the masculine gender of the given noun, we need to consider the corresponding masculine term that represents a male counterpart in the same religious context.

Options:

a) Maid - A maid is a female domestic worker. This option does not represent a male counterpart in the religious context of a nun, so it is not the correct answer.

b) Monk - A monk is a male religious practitioner who lives a contemplative life devoted to prayer, meditation, and religious study. This term represents the male counterpart to a nun and is the correct answer.

c) Steward - A steward refers to a person who manages or supervises affairs or property. While this term can be used for both genders, it does not specifically represent a male religious practitioner, so it is not the correct answer.

d) Man-servant - A man-servant refers to a male domestic worker or servant. This term does not specifically represent a male religious practitioner, so it is not the correct answer.

Conclusion:

The correct masculine gender for the noun "nun" is "monk". A monk is a male religious practitioner who lives a contemplative life devoted to prayer, meditation, and religious study.