$ATP$ is formed in

Mitochondria are the storehouses or powerhouses of

Which statement is correct regarding mitochondria?

Give scientific reason: Mitochondria is called the powerhouse of the cell.

Which statement is incorrect regarding mitochondria?

Assertion $A$: Mitochondria are the powerhouse of the cell.
Reason $R$: The sites for cellular respiration,specifically the $Krebs$ cycle and oxidative phosphorylation,are located within the mitochondria.
Which option is correct for Assertion $A$ and Reason $R$?