After taxes, Xue clears $6,400 in income each month. Her mortgage is currently $350,000 and her monthly mortgage payment is $2,200. Xue has decided to purchase life insurance and she asks her insurance agent, Cinzia, to determine the appropriate amount, accounting for inflation. Assuming an annual investment return of 4.5% and an average annual rate of inflation of 2.5%, what is the approximate amount of life insurance Xue needs using the income replacement approach? a) $1 million b) $2 million c) $3 million d) $4 million