Final answer:
Option (A), The mitochondria are the site of ATP production from the chemical energy of glucose during cellular respiration, and are thus known as the cell's energy factories.
Step-by-step explanation:
The site of conversion of the chemical energy of glucose to ATP is the mitochondria. Mitochondria are often referred to as the "powerhouses" or "energy factories" of the cell due to their role in making adenosine triphosphate (ATP), which is the cell's main energy-carrying molecule.
This process, called cellular respiration, involves several stages including glycolysis in the cytoplasm, the Krebs cycle, and the electron transport chain, which are housed within the mitochondria - specifically across the inner membrane with its folds called cristae. During these stages, oxygen is used, and carbon dioxide is produced as a waste product, which we exhale.