Final answer:
A benign tumor is localized and does not spread to other tissues. In contrast, a malignant tumor invades surrounding tissues and can lead to secondary tumors elsewhere in the body through metastasis, which makes it more dangerous.
Step-by-step explanation:
A tumor is an abnormal mass of cells that arises from uncontrolled cell proliferation. There are two main types of tumors: benign and malignant. The essential distinction between these two types is that benign tumors remain localized and do not spread to other tissues, whereas malignant tumors have the potential to invade surrounding tissues and establish new tumors in different organs through a process known as metastasis.
Benign tumors generally do not pose a serious threat to health as they do not invade or damage adjacent tissues. However, malignant tumors grow beyond the original tumor boundaries, potentially shed cells into the bloodstream, and may lead to secondary tumors in various parts of the body. Moreover, malignant tumors can also undergo further genetic changes which may enhance their ability to metastasize and thrive at distant sites.
To directly answer your question: What distinguishes a benign tumor from a malignant tumor? The option (a) Malignant is the correct answer because malignant tumors are characterized by the capacity to invade neighboring tissues, whereas benign tumors do not. This invasive nature is what makes a tumor considered malignant.