The correct answer is A. 3421.
The first word, “grumbling,” is an adjective that describes the subject of the sentence, “she.” The second word, “always,” is an adverb that modifies the verb “was.” The third word, “she,” is the subject of the sentence. The fourth word, “was,” is the verb of the sentence.
The sentence can be read as follows: “She was always grumbling.” This means that the subject of the sentence, “she,” was always doing the action of grumbling.
The other options are incorrect because they do not make sense in the context of the sentence. Option B, 3214, would read “she always was grumbling.” This is not grammatically correct because the adverb “always” should come before the verb “was.” Option C, 3412, would read “always she was grumbling.” This is also not grammatically correct because the subject of the sentence, “she,” should come before the verb “was.” Option D, 3241, would read “she was always grumbling.” This is the same as the correct answer, but it is not in the correct order.