The diseases that spread from one person to another through water, food, air…

Diseases are broadly classified by how they arise. One major classification is by mode of origin and transmission: communicable (infectious) diseases are caused by pathogens (bacteria, viruses, protozoa, fungi) that pass from an infected person to another person through a common vehicle such as contaminated water, food, or air, or through direct contact. Diseases that instead originate from an individual's own genetic makeup, from conditions present at birth, or from other non-infectious causes do not spread from person to person in this way.

The question describes diseases that spread from one person to another through water, food, air, etc. This is exactly the defining feature of communicable diseases, so Communicable diseases is the correct answer.

Checking the remaining options against their own definitions confirms none of them matches a person-to-person transmission route:

• Genetic diseases arise from abnormalities or mutations in an individual's own genes; the mutation itself is not transmitted through water, food, or air.

• Acquired diseases is a broad umbrella for any condition developed after birth, whatever the cause (infection, environment, lifestyle, injury); the term itself does not specifically describe the water/food/air transmission mechanism named in the question.

• Congenital diseases are present at the time of birth, resulting from genetic or developmental factors during pregnancy, not from transmission between people after birth.