Our school district should switch to single-gender classrooms. Which of the following supporting details provides the most relevant and
credible evidence for the claim?
A. Results from a nationwide survey show that by a wide margin both
male and female students who have experienced both mixed and
single-gender classrooms prefer single-gender.
B. The most recent vote on the single- versus mixed-gender
classroom issue saw our school board deadlocked at 3-3, and,
with the seventh member on vacation, no majority could be
achieved.
C. Studies from the National Education Board show that students
from single-gender classrooms score roughly the same on
standardized tests as students in mixed-gender classrooms.
D. My cousin Jacqueline's high school will switch to single-gender
classrooms in the fall, and she says she wouldn't be surprised if it
helped her concentration in the classroom.

i guess a or b...

but if i'm aloud to add my two sense... this is a horrible thing to do what about the kids who don't feel like they fit in nether label "boy or "girl" ? it's not healthy.

Explanation:

anyways have a good day!^^ <3

to eliminate ambiguous remote or broad reference it is necessary to focus on anaphoric reference. by definition "anaphoric reference means that a word in a text refers back to other ideas in the text for its meaning." the references should be clear and leave no room for ambiguity.

in the first case the pronoun it probably refers to the car but it has not been mentioned before so we should replace it for the car. in doing so the statement becomes clear.

in sentence number   two   the pronoun he refers to charles dickens the author. yet, the first half of the sentence is about the book a tale of two cities. to repair this it would be better to rephrase the first half : after i read   a tale of two cities by dickens, he so as to remove the remote reference.