Concept:Antonyms are words with opposite meanings. Here, 'innocent' means not guilty of a crime or offence.Explanation:The word 'innocent' describes someone who has not committed a wrong. The word 'guilty' means responsible for a wrongdoing. These two words are direct opposites, making 'guilty' the correct antonym. The other options do not show opposition. 'Clever' means quick to understand, which is unrelated. 'Ignorant' means lacking knowledge, not opposite to innocence. 'Active' means energetic, also not opposite. Hence, only 'guilty' fits.Answer:D. guilty