Answer: B. 11%
Explanation:
Let A = Event that students eat breakfast in the morning.
B= Event that students floss their teeth.
We are given P(A)=57%=0.57
P(B)=80%=0.80
P(A∩B) = 46% =0.46
Now, the probability that a student from this class eats break feast but does not floss their teeth :-

Hence, the probability that a student from this class eats break feast but does not floss their teeth= 11%