Christine is a cash basis taxpayer with the following transactions during the year: Cash received from sales of products Cash paid for expenses (except rent and interest) Rent paid on a leased building for 24 months beginning December 1 Prepaid interest on a bank loan, paid on December 1, for the next 3 months Four months' rent received on a leased building, on October 1 $90,000 $30,000 $54,000 $6,000 $8,000 Show calculations for Christine's income from her business for this calendar year