Jenna is experiencing an increased output of her oil - and sweat-producing glands. what other physiological changes is she probably experiencing at this time

The reason why Jenna is undergoing to stage of having increase output of oil and sweat production glands is because she is undergoing to stage of puberty. And because of this, it is likely that she is going to have and produce hair from her underarms as she has already undergone to the stage of having sweat production glands.