Which of the following diseases is both non-infectious and a leading cause of death in humans?

Cancer

The correct answer is (a) Cancer.

Cancer is a non-infectious disease that arises due to the uncontrolled growth and division of abnormal cells in the body. It is a major cause of death worldwide, contributing to a significant number of fatalities each year. Unlike infectious diseases that can be transmitted from person to person, cancer is primarily caused by factors such as genetic mutations, exposure to carcinogens, lifestyle choices, and environmental factors. It is characterized by the development of tumors or the invasion of malignant cells in various organs and tissues, leading to impaired organ function and potentially fatal outcomes.

AIDS is an infectious disease caused by the human immunodeficiency virus (HIV). HIV attacks the immune system, making it difficult for the body to fight off infections. AIDS is not a leading cause of death in humans.

Asthma is a chronic respiratory disease that causes inflammation and narrowing of the airways. This makes it difficult to breathe, especially during an asthma attack. Asthma is not a leading cause of death in humans.

Typhoid is an infectious disease caused by the bacterium Salmonella typhi. Typhoid fever is characterized by high fever, headache, fatigue, and diarrhea. Typhoid is a leading cause of death in developing countries, but it is not a leading cause of death in developed countries.

Therefore, cancer is the non-infectious disease that is a leading cause of death in humans.