NADH FADH2 and finally Oxygen which is not technically used in transfer, but it is the last electron acceptor at the electron transport chain.<span />
The answer is; Biodiversity resulting from few ancestors
Adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. The parts of the population in the different ecologies begin to adapt to their local environments. Due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. They, therefore, diverge to different species sharing a common ancestor.
The correct answer is option B, that is, the release of calcium ions makes actin and myosin to combine with each other.
At the time of the stimulation for a muscle contraction, calcium is discharged into the fiber. It combines with troponin and instigates it to move tropomyosin, exposing the binding site for the myosin cross-bridge. Thus, the face of the actin filament is now free to combine with myosin heads to initiate contraction of the muscle.
The effects that silt runoff has on coral reefs would be C. It damages reefs by blocking sunlight and burying the reefs.
We know that it wouldn't be A or D because the problem mentions in the first chunk that reef conditions are not improving, leaving us with the choice of B or C. From the second chunk of text, we learn that the algae that polyps rely on is dependent on the sunlight and that the coral needs non-stagnant, or moving, water to stay alive. This is addressed by C, while B mentions something non-related to the question.
Hope I could help!