From LimeSurvey Manual
Display columns (display_columns)
This setting allows you to display the answer options in more than one column. Add this attribute and a value indicating the number of columns you wish the question to use. It is recommended to limit the number of columns to the number of answers.
- Any positive integer value greater than 0
- If you have 3 answers options and you want to show these horizontally, set this option to "3" instead of vertically.
- If you have 6 answers options and you want to show these in two columns (3 per column), then set this option to '2'.