Concept:A synonym is a word that has the same or nearly the same meaning as another word.Explanation:The word “Lethal” means capable of causing death. (घातक)“Fatal” also means causing death or disaster. (प्राणघातक)So “fatal” is the correct synonym.Other options are wrong because:- “Harmless” means not causing harm – it is the opposite.- “Healthy” means in good health – unrelated.- “Strong” means having power – not the same as deadly.Answer:C. fatal