It doesn't know if it's a pension, 401K or IRA 1099R.
Say all of it is the RMD. If you are 70 1/2 it will ask you if it is the RMD. Say yes. Anything your pension pays you is considered to be the RMD.
One reason it might ask is to determine if your 1099R is eligible to roll over to another qualified retirement account. Which a RMD is not eligible.
