Well Primary Succession means you are the first organisms of that area after it is destroyed completely or if it's new. Secondary Succession is when an area is not destroyed completely but the organisms that remain colonize the area again. I believe it's C.
Each patient is different from any other ,
I'd say A: tidal waves. B, C, and D don't really seem to fit for me.
Answer:
The krebs cycle produces two ATP and energy carrying molecules that are used to produce more ATP in the electron transport chain.
Explanation: