Determine which of the sentences is written in active voice.
a) the biography has been returned to the library.
b) the nathaniel hawthorne essay was written by my best friend.
c) i made a better grade on my essay than i thought i would make.
d) is being read by all of the english classes.
eliminate

I belive its B :) Because active voice includes the doer of action, the action, and the reciver of action.

for example

At each concert, the Soprano (doer) sang (action) at least one tune (reciver of action)  from a well known opera.

hope this helped

eroupe is a great mideval place and alot of wars went on alao

d: social contract theory