Hello Rod and welcome to Ariba Exchange!
FYI, I've moved this to the Sourcing section and asked a few experts from that support team to weigh in on your question.
Welcome to Ariba Exchange.
You can create a Question by selecting acceptable values as "List of Choices" and allow suppliers to select multiple values and/or other values if the response is not in the specified list.
Please refer to the attached screen print to see the different options.
Alternatively you can also have them submit other responses as attachment or comments.
Multiple Answer.bmp 3.5 MB
That looks like it will work.