This is referred to as Sleep Apnea.
Answer:
C. Both light tan and dark tan body color provided an advantage to the crabs on this beach, but not necessarily in other crab habitats.
Explanation:
The changes in the number of light tan and dark tan body color of crabs that occured can be described as a diversifying or disruptive selection.
This disruptive selection occurs when individuals with extreme traits on both ends of the spectrum become selected against individuals of ntermediate or medium traits.
In the case of the crab, their environment favors the selection of both extreme values as against those intermediate individuals, as both light tan and dark tan body color of the crabs gives them advantage over others in this particular environment. This may only be obtainable in this environment or similar beach environment with the same settings and conditions.
