Answer:
The answer to your question would be that the most effective substitute for the underlined part of the sentence is the following one: In England, she met (B).
Explanation:
"While Sara was traveling in England" is an introductory clause. Introductory clauses are dependent clauses that provide background information or set the scene for the main part of the sentence, the independent clause. They start with adverbs such as although, after, because, etc. In this case, the introductory clause is introduced by the adverb while.
