Which of the following is NOT a true bi-conditional statement? A It is noon if and only if it is 12:00 PM.
B Two segments are congruent if and only if they have the same length.
C An angle is right if and only if its measure is 90°.
D I am a violinist if and only if I am a musician.

d

because your a musician you cant be a true statement I am wrong

It can't be the first one because if y was 5 and x is 0 that would make both sides equal.
It's not the last one because if y was 1 and x is 7 that would make the right side bigger and that's not correct. 
Your answer should be - B. (1, 7)
I hope it helps.