Answer :
Final answer:
The underlined phrase that serves as an object is in sentence B: The pyramid of Khufu was converted with a limestone layer long ago.
Explanation:
The underlined phrase in the sentence is an object in sentence B: The pyramid of Khufu was converted with a limestone layer long ago. An object is a noun or pronoun that receives the action of the verb. In this sentence, the noun phrase 'a limestone layer' receives the action of the verb 'converted'. The subject of all the sentences is 'The pyramid of Khufu'.
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