B. rabbits changing fur color
The answer would be both!
The substrate of the citric acid cycle which can block respiration when it is present in excess is MALONATE. Malonate inhibits respiration by competing with succinate dehydrogenase for its acitve site. Malonate binds to the active site without reacting, thus competing with succinate. This disrupts the cellular respiration in the cell.
A all cells have the same number of chromosomes hope this helps!! and C