It looks like the "correct" answer was supposed to be "2.2 and 5.8" -- another poster mentioned the server sends answers to the client. But P(X=3 or X=4 or X=5) is .598.

It looks like they used the normal cdf approximation of the Bernoulli distribution, which would give .6857.

That is some horrible approximation then! The closest range sum to 68% is for {3,4,5,6} summing to 70%, but even if available as an answer, the only correct answer remains "none of the above".