Answer the following question given this paragraph: 

Two separate membranes form the mitochondrion. The inner membrane folds into cristae which divide the organelle into three compartments: the intermembrane space (between outer and inner membranes), cristae space (formed by infoldings of the inner membrane), and the matrix (within the inner membrane). The Krebs Cycle takes place within the matrix. The compartments are critical for the electron transport chain structure and function. Glycolysis occurs in the cytoplasm of the cell, with the products of glycolysis entering the mitochondria to continue cellular respiration.


Q: How many membranes form the mitochondrion structure of a cell?

 Choices:

- one

- five

- three

- two

A:
two
