[strike]Could you explain a little further? Because I don't understand the problem.
In Matrix questions you have answer options (horizontal) and subquestions (vertical).
In normal Matrix-Questions you can only give one answer per row. If you use the matrix per column you can only give one answer per column.[/strike]
Forget about it. I just saw that you are looking for multiple answers.
Have a look at the manual, it explains which question type to use:
manual.limesurvey.org/question_types
Specifically
manual.limesurvey.org/question_types#Array_.28Numbers.29
.
But please take your time to have a look at the whole section "question type". It really makes sense to read this before you start any serious work with Limesurvey. It shouldn't take much more than 20-30min to get a good idea of the questions types available in Limesurvey. It is worth the time investment.