Bianca and dave are a married couple filing a joint tax return. they have a combined gross income of $81,031 and claim four exemptions. they can make an adjustment of $2,914 for business expenses, an adjustment of $1,939 for business losses, a deduction of $4,140 for medical expenses, an adjustment of $4,825 for contributions to their retirement fund, and a deduction of $2,420 for charitable donations. if exemptions are worth $3,650 apiece and the standard deduction for a joint return is $8,350, what is their total taxable income? a. $50,193 b. $41,843 c. $48,403 d. $52,793