"Quarantine" refers to a period during which individuals (people or animals) are kept isolated to prevent the spread of infectious disease. This term became widely known during health emergencies like the COVID-19 pandemic. Examples: - "The dog was kept in quarantine for 10 days after a bite incident." - "Travelers had to undergo quarantine upon arrival." Why other options are wrong: - "Quarter": means a portion or 25%, not related to isolation. - "Imprisonment": forced confinement as punishment by law. - "Custody": being kept or detained, but not specifically for disease control.