Many toxins and poisons block certain enzymes in the mitochondria. For example, many fruits, including apricots, apples, plums, peaches, and cherries, contain seeds and pits that can cause the formation and release of the poison cyanide if they are ground and ingested. Cyanide binds to an enzyme in the inner mitochondrial membrane critical to energy production. Why would this be fatal for a cell?
A. Cells would not be able to reproduce.
B. Cells would not be able to undergo adequate organelle functioning.
C. All of the answer choices are correct.
D. Cells could have inadequate distribution of ions.

Option A is correct because the reproduction of the cell implies arrangement of chromosomes, making of proteins, organelles, cytokinesis and other cells process that need energy since the mitochondria is not working properly there isn't an appropriate organelle function ( option B).

Option D is correct because ATP is needed for the membrane proteins to undergo active transport. For example the sodium-potassium pump is crucial for the balance of ions. With no energy the protein involved in this process would not work.