HOTSPOT
Your company uses Microsoft SharePoint Online. You share a file named Document1 with several
users, as shown in the image below.
You need to ensure that the users can display, but not change, Document1.
What should you do? Select the correct answer from each list based on the information presented in
the image. Each correct selection is worth one point.
Answer: 
I would say the first option is: Open the Shared With dialog box for Document1 and remove the user.
In reality after going to this dialog box, you need to go to Advanced and delete the user, but we’re talking about external users here not guest users, so deleting the guest links doesn’t remove the permissions for these users.
Second choice is right.
The answer is right.
First remove then re-create a link with the good rights.
https://support.office.com/en-us/article/Share-sites-or-documents-with-people-outside-your-organization-80e49744-e30f-44db-8d51-16661b1d4232
answer is correct
Yes answer is correct.
I have tried this in practice and if ‘require sign in’ is not ticked, then it is not possible to delete the user, so you need to remove the link. If it was ticked then the answer would be delete the user or change the users permissions.
Starlin is wrong, John L explains it right. And btw if you invite a user and require sign-in, you will not find this user listed in the ‘Shared with’ list until he clicked on the invite.