The correct answer is option 4, Mitochondrium.

Cellular respiration is the process by which cells convert nutrients into energy in the form of ATP (adenosine triphosphate). This process occurs in the mitochondria, which are often referred to as the "powerhouses" of the cell.

Option 1, Endoplasmic reticulum, plays a role in protein synthesis and lipid metabolism, but not in cellular respiration.

Option 2, Golgi body, is responsible for modifying, sorting, and packaging proteins and lipids in the cell, but not for cellular respiration.

Option 3, Lysosome, is a membrane-bound organelle involved in cell waste disposal and breaking down cellular debris. It is not involved in cellular respiration.

Therefore, the correct answer is option 4, Mitochondrium, as it is the site of cellular respiration, producing ATP for the cell`s energy needs.