Thank you for replying. By playing with your idea, I found that the right margin governed. If both margins were set equally, then the RadioButton might not be centered. By either increasing or decreasing the right margin, I could center the RadioButton.
I like your idea of simply eliminating the caption and placing text above.
I want to create several questions for a recipient to rate a service from one to five, with five being the best. Knowing that the leftmost RadioButton is worst and the rightmost RadioButton is best, I don't require having a caption with its numerical value for every radio button. I can just place the numerical values at the top of the list of questions, and proceed from there.
Thank you for your help.