Sarah (single) purchased a home on January 1, 2008 for $600,000. She eventually sold the home for $800,000. What amount of the $200,000 gain on the sale does Sarah recognize in each of the following alternative situations? (Assume accumulated depreciation on the home was $0 at the time of sale.)

a. Sarah used the home as her principal residence through December 31, 2017. She used the home as a vacation home from January 1, 2018 until she sold it on January 1, 2021.

b. Sarah used the property as a vacation home through December 31, 2017. She then used the home as her principal residence from January 1, 2018 until she sold it on January 1, 2021.

c. Sarah used the home as a vacation home from January 1, 2008 until January 1, 2020. She used the home as her principal residence from January 1, 2020 until she sold it on January 1, 2021.

d. Sarah used the home as a vacation home from January 1, 2008 through December 31, 2014. She used the home as her principal residence from January 1, 2015 until she sold it on January 1, 2021.