The core concept here is understanding financial terms. 'Net income' is a financial metric that indicates the total revenue minus all expenses, which includes operating costs, taxes, and interest. Option C correctly defines 'net income'. Option A refers to 'total revenue', which is not the same as 'net income' because it does not account for expenses. Option B refers to 'expenses', which are subtracted from revenue to calculate 'net income', not the 'net income' itself. Option D is specific to legal expenses, which are a part of the expenses that reduce 'net income', but they do not define 'net income'.