Choose the correctly punctuated sentence.
a) The profitability of his business means he is in the top tax bracket: he pays 39. 6 percent tax on his earnings.
b) The profitability of his business means he is in the top tax bracket he pays 39. 6 percent tax: on his earnings.
c) The profitability of his business means he is in the top tax bracket he pays 39. 6 percent tax on his earnings.