1.To change the visibility, navigate to General Applications > Questions, then hover over Questions again bring up a dropdown menu and select Import Data.

Accessing the Import Data
Once in the Import Data section, there are two tabs; one for information that is visible to Applicants and another that is information visible to Administrators. Within each tab is the Reviewable column, which indicates the pieces of data that are also visible with Reviewers. 
Selecting a Question to Edit

2. To change a questions visibility, click the Edit button. 
3. Unmark the Reviewable checkbox. 
4. Click the Update for All Opportunities button. 
Unchecking the Reviewable Box
5. Click the Update Questions button on the main Import Data section. 
6. Repeat these steps for all questions that should be visible to reviewers.