What is the primary use of chemotherapy?

The primary use of chemotherapy is to kill fast-growing cells, which is particularly relevant in the treatment of cancer. Chemotherapy targets the rapid division of cancer cells, which is characteristic of many malignancies. These treatments use powerful chemical substances that can disrupt the processes leading to cell division, effectively slowing or halting the growth of tumors.

While some other options touch on important aspects of medical treatment, they do not directly align with the specific mechanism and goal of chemotherapy. For example, chemotherapy is not designed primarily for the treatment of infectious diseases, reducing inflammation, or replacing damaged tissues, which are goals served by different classes of drugs or therapies. The focus of chemotherapy on rapidly proliferating cells is what makes it a cornerstone in oncological treatment.