Size and alignment are crucial in your text boxes, or within your drag-and-drop components in a drag-and-drop question. Different sizes and alignments can cause confusion within your slide.
On the left slide, you can see that the drag components and drop targets are not of the same size. Additionally, the drag components don't fit into the drop targets, and the text is not aligned.
On the right slide, you can see that the drag components and drop targets are of the same size. Furthermore, the text is aligned. Tip: copy and paste the drag components and drop targets so that they are exactly of the same size. Now you only need to adjust the text and colour of the copied ones.