Enter Prior Year Roth IRA Contributions" not applicable?

i have a 1099-R that is annuitized and I am receiving monthly payments.  The amounts being send to me are RMD.           Why do I have to answer this question:   Enter Prior Year Roth IRA Contributions"

i have not contributed to it for many years until I turned 70-1/2 and started receiving rmd payments.   Thankyou.  This is confusing.  i am on turbo tax deluxe