Which organelle is known as the powerhouse of the cell?

Which of the following representations correctly explains the function of a mitochondrion?

Mitochondria are also known as .......

Which process occurs in the part labeled 'a' in the given figure?

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.

The power house of the cell is ......