Determine the applicability of Section 691(a) to each.

On 6/1/18, A sold his apartment building to his son, B for $400,000. Pursuant to the contract, B gave A a note (bearing interest at the prevailing market rate) for the full purchase price. The note required a single payment of principal and accrued interest on 1/1/20. At the time of sale, the property was unencumbered and A had an adjusted basis of $100,000. On 8/1/18, A died. B's note passed as part of the residue of A's estate to W, A's wife, and was distributed to her on 3/1/19. B made full payment of the obligation to W on 1/1/20. Assume in the alternative that on 8/1/18 the note had the following fair market value:

i. $400,000

ii. $390,000

iii. $410,000