Historians debate how the Great Pyramids of Giza were constructed with such precision. While some scholars think the stones _________ using massive ramps, others believe that a system of internal spiral tunnels was utilized.

8
writing

Which choice completes the text so that it conforms to the conventions of Standard English?

A

moved

B

are moving

C

were moved

D

had been moved

Correct Answer: C

Choice C is the best answer. The sentence describes a theory about a past event. The passive voice in the simple past tense ("were moved") is required because the stones received the action.