Question

4. In the passive voice, the agent is very often not mentioned. When it is mentioned, it is introduced by the preposition ... at the end of the sentence
a. ( ) in In
b. ( ) on
c.( ) at
( ) by
a.( )a, b, c, d.
b.( )b, b, d,c.
c.() b, b,c,d.
d.()d,c,a, b. d.​

Answer 1

A preposição usada é "by".

Ex.: The cake was baked by my father.

The trash was taken out by the boy.

The school was set ablaze by the arsonist.