Step 1: Understanding the Context:
The sentence requires a noun to complete the expression "declared his..." In this case, "innocence" is the correct noun that follows "declared his." Step 2: Analyzing the Options:
- Innocence: The correct noun that refers to the state of being innocent, fitting the structure of the sentence.
- Innocently: This is an adverb, and adverbs are not used to complete this sentence.
- Innocent: This is an adjective, but the sentence requires a noun.
- By innocent: This is grammatically incorrect as "by" is not needed here. Step 3: Conclusion:
The correct word is innocence, as it is a noun and fits the context of the sentence.