Having a drop-down menu with multiple selections as an answer to a question in a Form is a popular question but we don't have this feature due to the ways the forms report out.
We have a suggested workaround that will make you achieve the same goal.
You can get the same work done by using the Section heather and the Yes/No questions.
We will show you how to do that on an example when you need to select between different products the ones that are out of stock.
We have the Single selection drop-down as selecting the Product that is out of stock.
For multiple selections, you can select the Section heather and the Yes/No questions.
You can do that by adding a Section heather question type in the form and as a question type in something like „What products are out of stock?“. Then you can list the products below as Yes/No questions.
It's still easy from the rep's perspective but you're actually able to report out on this information and see the out of stock trends for each of the listed product.