Question

the boy wrote the answer.The answer was incorrect.(use adverbial phrase)

Answer 1

The boy wrote the answer while he answered incorrectly.  Here the phrase is added he answered incorrectly. It is an adverb that qualified the answer. While is working as a adverbial joiner.

The sentence gets combines into one sentence and the meaning has remains the same. The consistency of the verb has been well maintained. From two simple sentences, it is changed into a complex sentence.

Answer 2

Answer:

The boy wrote the answer which was incorrect. Hope that it will be helpful :-):-)....