Why is the TCA cycle the central pathway of metabolism of the cell?

ANS:B - Its intermediates are commonly used by other metabolic reactions

There are certain reactions that can feed intermediates into the TCA cycle, these reactions are called Anaplerotic Reactions. As these intermediates are also part of other systems, it can suggest that process of TCA is flexible and will adapt to accommodate different conditions of the cell. e.g. when there is sufficient energy, TCA is less likely to take place.