Question

which of the following is not a secondary sex charatceristic? a breast development b deepening of voice c public hair d menstruation

Explanation:

Secondary sex characteristics are physical features that develop during puberty due to hormonal changes and are not directly involved in reproduction. Breast development in females, deepening of voice in males, and public - hair growth in both sexes are secondary sex characteristics. Menstruation is a primary reproductive function related to the female reproductive cycle, not a secondary sex characteristic.

Answer:

D. menstruation