6. Butler Co. reported pretax accounting income in 2018, 2019, and 2020 of $100 million, plus additional 2018 income of $40 million from installment sales. The installment sales collected as follow: $10 million in 2019 and $30 million in 2020. The statutory tax rate is 40% for the three years. The installment sales were collected as follows:

A. $40 million

B. $52 million

C. $44 million

D. $12 million