How do I make a certain number of rows or columns mandatory in a matrix question?

How do I make a certain number of rows or columns mandatory in a matrix question?

To make a certain number of rows or columns mandatory in a matrix question:

  1. In the Question box, type your question.
  2. In the Required number of rows dropdown list, select the number of rows you want to keep as mandatory. This can be in the form of at least, at most, exactly or in between. This option appears only if the Make this question mandatory checkbox is selected.