the correct option is pregnancy, age, and puberty.
The human skin comprises of sebaceous glands. These glands secrete oily substance called sebum. Sebum is composed of fats. Sebum traps moisture to keep the skin moist. The amount of sebum produced is depends on many factors.
When androgen level is increased, the production of sebum is also increased. During puberty changes in hormone occurs, more sebum is produced. During pregnancy level of androgen is also high, more sebum is produced. Sebum production also varies with age.