Form 4972 Tax on Lump-Sum Distributions

My brother died in 2019. He had a pension plan. I was the beneficiary of the pension plan.  I received a 1099-R. 1099-R line 1 is $6769. 

Using Turbotax I had a choice -

Yes, let's see if Gary qualifies for the special averaging method or

No, let's finish up this 1099-R for now. I can come back later if I change my mind. 

I am assuming the special averaging method is Form 4972 and "No" is ordinary income. 

I tried both.

Form 4972. I answered the questions for lines 1 through 5B. 1-Y, 2-N, 3-Y, 4-N, 5a-N and 5b-N. This lets me use Form 4972. 

The Federal Tax difference between ordinary income and Form 4972 is $1130.

Which method should I use? Can I use Form 4972? I afraid if I use Form 4972 and found later I should have reported as ordinary income, I will need to pay the $1130 difference.