Question

lack of adequate sanitation, drinking water polluted by human and animal waste, and the fact that people rarely bathed or washed their hands helped to spread the __________
a contagion
b word
c cure
d none of the above

Explanation:

Lack of sanitation, polluted water, and poor hygiene habits contribute to the spread of diseases or contaminants. "Contagion" refers to the spread of a disease - causing agent. "Word" is unrelated in this context. "Cure" is something that heals, not something that spreads. So the most appropriate term is "contagion".

Answer:

A. Contagion