Which function describes what a mitochondrion does?

Mitochondria are often referred to as the "powerhouses" of the cell because their primary function is to produce adenosine triphosphate (ATP), the energy currency of the cell, through the process of oxidative phosphorylation. They also play crucial roles in regulating cellular metabolism, calcium homeostasis, and apoptosis (programmed cell death). Additionally, mitochondria are involved in the production of reactive oxygen species and the metabolism of certain biomolecules.