Which of the following sentences is written in passive voice?
a. When riding a bike, most people wear a helmet and other protective gear.
b. You should wear a helmet and other protective gear when riding a bike.
c. Timothy wore a helmet and other protective gear when riding a bike. or
d. When riding a bike, a helmet and other protective gear should be worn.
The correct answer id d.: When riding a bike, a helmet and other protective gear should be worn..
The passive phrase in this sentence is "be worn" or "should be worn" and you can see that it's a passive because it has a form of "to be" plus a past tense of the verb.
