Dry Areas of the Skin Such as the Inner Forearm

Dry areas of the skin such as the inner forearm are seen to contain the most diverse populations of microbes.Suggest a reason why this is observed: (Select all that apply)

A) Increased exposure to atmospheric microbes which may vary with geographical location
B) Maximum oil production occurs in this region
C) A mix of hair,sweat and sebaceous gland environments exist here
D) The environment is less salty than others on the skin
E) All are plausible explanations for the observation