Answer:
The correct answer is "nevertheless"
Step-by-step explanation:
In the sentence, the only possible option is "nevertheless" since it is the only words that expresses contrast. According to the meaning of the sentences, contrast should be reveal between them. Another synonym for nevertheless is "however".
The adverb "therefore" is used to express cause and effect.
The adverb "immediately" expresses time.
The adverb "otherwise" means "or else"