Answer:
most likely C
Explanation:
human skin has a variety of different tones and therefore is polygenic
also, free Jay pic cuz she da best
I think the crust is formed by volcanic activity
Rods and cones are similar in that they both release glutamate as the primary neurotransmitter. During signalling the rod and cone photoreceptors signal their absorption of photons via a decrease in the release of the neurotransmitter glutamate to bipolar cells at its axon terminal. Every rod and cone photoreceptor release the same neurotransmitter, glutamate.
that would be C phisical characteristic