The answer i got is not one of the options, and i am very confused, because now i don't know what to do?

if triangle abc is reflected across line m, where will the new coordinates be located?
a’(-2, 4); b’(-7, 8); c’(2, 8)

a’(7, -8); b’(2, -4); c’(-2, -8)

a’(2, -4); b’(-2, -8); c’(7, -8)

a’(2, -4); b’(7, -9); c’(-2, -9)

coordinate's i got:
a'(2,2), b' (7,-3), c' (-2,-3)

can someone clear this up for me?