Question

how is isolation to prevent the spread of disease different from quarantine?
a people are isolated to prevent the outbreak of infectious diseases; people are quarantined to contain diseases within a certain area.
b people are isolated to contain highly infectious diseases; people are quarantined to contain diseases that are not dangerous.
c people are isolated when they are already sick; people who are quarantined might have been exposed to an illness, but are not sick.
d people are isolated within a region or state; people are quarantined when they need to be prevented from entering a country.

Explanation:

Isolation is for those already ill with a contagious disease to prevent spreading it. Quarantine is for those who may have been exposed but are not yet sick to see if they will develop the disease.

Answer:

C. People are isolated when they are already sick; people who are quarantined might have been exposed to an illness, but are not sick.