Radio questions may be duplicated using the Clone button at the upper right of the question's page. It's marked in green here.
After pressing Clone you will see a modal showing all the original question's answer options and settings. The Question Text field will show the text of the original question followed by (clone). Make any desired changes and then move down to the Answer Options.
Reword the answer options as needed. Use the drag handles or up/down arrows (outlined in green below) to rearrange the options. To remove an option, use the X to the right of each row (outlined in red below). To add another option, use the + Add another answer option button at the bottom right of the answer options section (outlined in blue below).
Change the Question Settings as needed to suit your new question.
Choose a question type for the new question.
Finally, hit Submit to create the new question.