Multiple choice Directions: Choose the word or phrase most similar in meaning to the keyword. Immune secure imprison unsafe impure impute Reveal answer Fill a bubble to check yourself A Correct answer Explanation Immune means protected or secure from disease, infection, or influence. Secure is the correct synonym as it captures the sense of protection. Imprison, impure, and impute are unrelated meanings. The prefix 'im-' here means 'not' susceptible to.