Hartzell Inc. had the following data for 2020 , in millions: Net income =$600; after-tax operating income [EBIT (1T)]=$700; and Total assets =$2,000. Information for 2021 is as follows: Net income = \$825; after-tax operating income [EBIT (1 T )]=$850; and Total assets =$2,500. Assume the firm had no excess cash. How much free cash flow did the firm generate during 2021? a. $325 million b. $1,325 million c. $1,350 million d. $350 million e. $625 million