Which sentence is written in the passive voice? marjorie waved at the bicyclists. the bicyclists were waved at by marjorie.

When the sentence is written in the passive voice, the subject in the sentence becomes the receiver of the action of the verb. The sentence that is written in the passive voice is: The bicyclists were waved at by Marjorie. In this sentence, the subject is the "bicyclists" which receives the action "were waved". The correct answer would be the second option.

Which sentence is written in the passive voice?

The sentence that is written in passive voice is the following:

The Bicyclist were waved at by Marjorie. The reason being that in the sentence, the subject which is “Bicyclists” is given the action being waved at.

I hope it helps, Regards. 

1. He cursed his great grandfather because it broke the flute