Answer- B. It protected civil rights in polling places.
Explaination(via the photo)- We can see that voting would an unfair toll on lower income families and People Of Color (mostly black), because high levels of testing were required to vote and at this time many poor and Black families were not able to access high levels of education, this Act was put in place to ensure that all could vote, and high level tests were not needed and would not discriminate against people.
Which concludes our answer b. It protected civil rights in polling places.
(read more using archive.gov)
Hope this helped. Good Luck!