Best way to show users that they have to select an option

1. What is used to allow the user to select one of the options displayed?
2. What allows the user to select only one option at a time from a group?

What is used to allow the user to select one of the options displayed?

Checkboxes allow the user to select one or more options from a set. It is usually best to present checkboxes in a vertical list.

What allows the user to select only one option at a time from a group?

Radio buttons allow a user to select a single option among multiple options. You can set the Choice Value of each option, for each button, as well as group these buttons by giving them the same Group Name.