Adding Answers To Answer Columns

so im trying to make a text quiz but whenever i go to add the answers into the columns i cant find where to drag the answers into the column. I have every answer already typed out and when i go to add them i just dont have the button or anything to add them to the cell. someone please help me because ive been looking for a whole day on how to do it and ive had no help. (i cant find an "edit cell" box. ive tried everything.)