Ileocecal sphincter tone decreases after distention of colon. This sphincter separates ileum and cecum and is under the control of vagus nerve.
The right answer is D.
The absorption of molecules at the level of the skin is carried out by passive diffusion for the molecules of low molecular weight (lower than 400 Da), the skin being covered with a lipoprotein film rich in water by its stratum corneum, rendering it little-permeable.
This absorption may be variable according to factors related to the skin such as stratum corneum's thickness, the state of hydration, the presence of cutaneous lesions or individual variations.
External factors may also modulate percutaneous absorption such as contact time, iontophoresis or the presence of specific adjuvants.
I think that these are A climate changes because they both got fur to match the snow/winter climate
I know it's not C cause this has nothing to do with food, and i don't think it's B either, so I think the best answer choice would be A