Concept:The word 'deteriorate' means to become progressively worse in quality or condition.Explanation:'Deteriorate' indicates a decline or degradation.'Worsen' means to make or become worse.Both words convey the same idea of declining or becoming less satisfactory.'Grow' means to increase; 'revive' means to restore; 'improve' means to make better.These are antonyms or unrelated to the given word.Hence, 'worsen' is the correct synonym.Answer:B. Worsen