What is the purpose of a bleaching agent?

A bleaching agent primarily functions to lighten skin discoloration, making it the correct answer in this context. These agents often work by reducing melanin production in the skin or providing a temporary lightening effect, which can help address issues like dark spots, hyperpigmentation, or uneven skin tone.

While other options may involve treatments or processes that relate to disinfection, food preservation, or flavor enhancement, they do not pertain to the primary role of bleaching agents. Disinfectants focus on killing germs on surfaces, flavor enhancers improve taste without affecting color, and preservatives aim at maintaining food quality rather than altering its appearance. Thus, the specific role of bleaching agents aligns clearly with skin lightening.