Pat sells real estate for $30,000 cash and a $120,000 5-year note. If her basis in the property is $90,000 and she receives only the $30,000 down payment in the year of sale, how much is Pat's taxable gain in the year of sale using the installment sales method? a. $60,000 b. $30,000 c. $15,000 d. $12,000 e. $0