First of all, if you look at it this way, the connection questions are actually corresponding. Now there are four questions, assuming they are A, B, C and D. What they actually need to connect should be A 1, B 1, C 1, D 1, so one is wrong and the other is definitely wrong, because of the connection questions.
The probability of two mistakes should be: choose two mistakes in four lanes and the other two are right. So the answer is: C42/A44=6/24= 1/4.