Final answer:
The adjective meaning cancer-causing is carcinogenic. Carcinogenic refers to substances that can induce mutations in DNA, leading to cancer.
Step-by-step explanation:
The adjective meaning cancer-causing is carcinogenic. This term refers to any substance or agent that has the potential to cause cancer. Cancer is a disease where cells divide uncontrollably, often leading to tumors and possibly spreading throughout the body. Most carcinogens induce cancer by creating mutations within the DNA, affecting genes that regulate the cell cycle. When the cell cycle is disrupted, cells begin to multiply rapidly and without the usual controls, leading to mass of abnormal cells called tumors, which may be benign or malignant. However, it is the malignant tumors that are cancerous as they invade surrounding tissues and spread to other parts of the body. It's crucial to distinguish between carcinogenic and the other terms listed. Benign is used to describe tumors that do not spread and are not cancerous, while malignant refers to cancerous tumors, and tumorous simply indicates the presence of a tumor which might be either benign or malignant.
Answer: a) Carcinogenic