How to setup a comment text box response for a single choice question

Summary

Requirement is to have comment text box for a single choice question

Content

Hello, 
We have a requirement to have single choice responses to the questions of the Learning Evaluation/assessment. 
For the “answer drop down list, change the order of the answers to: 
1. Yes 
2. No (please specify in comments section) 
3. Do not know (please specify in comments section) 

For each question that includes this answer drop down list, there has to be a comment box available per question. 
What is the possibility in the fusion application to achieve this?