Which of the following is a common form of chemotherapy?

Chemotherapy agents are the primary classification of treatments that are specifically designed to target cancer cells by inhibiting their growth and replication. These agents work by interfering with cellular processes, such as DNA replication or protein synthesis, which are crucial for cancer cell proliferation. Traditional chemotherapy is often administered as a systemic treatment, meaning it can affect the entire body, rather than targeting a specific area like localized therapies.

In contrast, radiation therapy utilizes high-energy radiation to kill cancer cells or shrink tumors, making it distinctly different from chemotherapy. Immunotherapy aims to bolster the body's own immune system to fight cancer, which is another separate modality. Targeted therapy, while also related to cancer treatment, focuses on specific molecular targets associated with cancer, rather than broadly targeting all rapidly dividing cells as traditional chemotherapy does.

Understanding the distinct characteristics of these treatments helps clarify why chemotherapy agents stand out as a common and essential option within cancer treatment regimes.