The figure below shows the structure of a mitochondrion with its four parts labelled A, B, C and D. Select the part correctly matched with its function.

Explanation

The correct answer is B (inner membrane) - forms infoldings called cristae. The inner membrane of the mitochondrion is folded into cristae, which increase the surface area and allow for efficient ATP production via the electron transport chain and ATP synthase. Option A is incorrect because the outer membrane does not give rise to the inner membrane; instead, it serves as a protective barrier. Option C is incorrect as cristae are not associated with possessing DNA; they are associated with ATP synthesis. Option D is incorrect because while the matrix is the site of the citric acid cycle, the respiratory chain enzymes are actually located in the inner membrane.