3. Eileen, an unmarried taxpayer, sells her residence in December 2020. Which of the following statements is correct? a) To qualify for the $ 121 exclusion, Eileen must occupy the residence at the date of the sale. b) Assuming that Eileen owned and occupied the house as her principal residence for at least the previous 5 years, the maximum $ 121 exclusion available to Eileen is $250,000. OC) If Eileen originally purchased the residence in December 2010, subsequently sold the residence to her cousin in December 2016, and then repurchased the residence back from her cousin in December 2018. Eileen could qualify for the $ 121 exclusion. (Note: When Eileen owned the residence, she also lived there. When she did not own the residence, she did not live there.) d) Only b. and c. are correct. e) a., 6., and c. are all correct