Determine the effects of the following on a cash basis taxpayer's gross income for 2019 and 2020. if an amount is zero, enter "0". gross income 2019 gross income 2020 a. on december 31, 2019, the taxpayer received a $1,500 check from a customer. the taxpayer did not cash the check until january 3, 2020. $ 1,500 $ 0 b. on december 31, 2019, the taxpayer received a $1,500 check from a customer. the customer asked the taxpayer not to cash the check until january 3, 2020, after the customer's salary check could be deposited. $ $ c. on december 31, 2019, the taxpayer received a $1,500 check from a customer. the check was not received until after the bank had closed on december 31, 2019. the taxpayer did not cash the check until january 3, 2020.