Which is the active voice of: “A road was built by the government”?

MCQ Quiz

7. Which is the active voice of: “A road was built by the government”?

a
The government built a road right outside their front door.
b
The government is building a road right outside their front door.
c
A road was being built by the government right outside their front door.
d
The road had been built by the government right outside their front door.