b$.$ Nell will receive $$1,000$ per month for $120$ months. If she dies before receiving all $120$ payments, the remaining payments will be made to her estate.

Only if the payments are classified as a property settlement $,,$ the payments are neither included in Nell's gross income nor deductible by Kirby since they are pursuant to a divorce agreement reached after $2018.$

c$.$ Nell is to have custody of their $12-$year$-$old son, Bobby. She is to receive $$1,200$ per month until Bobby $(1)$ dies or $(2)$ attains age $21($whichever occurs first$).$ After either of these events occurs, Nell will receive only $$300$ per month for the remainder of her life.

The monthly payments are considered part child support and part alimony

Regardless of the classification of the payments as child support or alimony $,,$ the payments are excluded from Nell's gross income as they are received by her, and Kirby may not deduct the payments.

d$.$ How would the answer to part $($b$)$ change if the divorce had been finalized in $2017?$

Even if the divorce were settled in $2017,$ the cash payments of $ per month as alimony because they $?$ cease upon Nell's death. Therefore, the payments would still be excluded from Nell's gross income and by Kirby.