In mdl-4990 was a report about a layout probelm with correct answer feedback in matching question.
The lang string writes: Correct answer is {$a}

The structure of the text is the following
The correct answer is: item1 <line break>
answer item 1, item 2<line break>
answer item 2, item 3<line break>

A better structure would be
The correct answer is:<line break>
item1 - answer item 1, <line break>
item 2 - answer item 2 <line break>
...

The student can't easily identify which item is selected to which correct answer.