Final answer:
Jenna's increased output of oil and sweat glands during puberty indicates other physiological changes such as the growth of pubic and underarm hair, body growth, and potential menarche.
Step-by-step explanation:
Based on the description that Jenna is experiencing an increased output of her oil- and sweat-producing glands, it is likely that she is going through puberty, a stage where the body undergoes several physiological changes.
During this time, girls typically experience a growth spurt, which includes the widening of the hips and the development of breasts.
Other changes that occur are the growth of pubic and axillary (underarm) hair, menarche (the beginning of the menstrual cycle), and sometimes an increase in height and changes in body composition.
Given the options provided, Jenna is probably experiencing growth of pubic hair (A), the beginning of body growth (B), and the appearance of underarm hair (D). Menarche (C) usually occurs after these changes but may also be occurring depending on where she is in the puberty process.