An expert in organ transplants, the chief surgeon of the hospital routinely spoke at conferences. The underlined portion of the sentence is known as a(n)

An Appositive

(The underlined sentence is:  An expert in organ transplants,)

Explanation:

An Appositive is a noun or noun phrase placed alongside another noun in the sentence, for the purpose of providing additional information about it. In the sentence above, the Chief Surgeon is the noun in the sentence and the introductory sentence, which is the appositive sentence provides further details about the Surgeon.

He is described as an expert in organ transplants, so the reader knows that the surgeon is a seasoned professional. The appositive can sometimes be just a noun in the sentence. Some sentences would also not lose much of their meaning even if the appositive is removed.

the correct answer is:   [d]:   " espionage " .

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