39.Alex Burg, a cash basis taxpayer, earned an annual salary of $80,000 at Ace Corp. in 2018, but elected to take only $50,000. Ace, which was financially able to pay Burg's full salary, credited the unpaid balance of $30,000 to Burg's account on the corporate books in 2018, and actually paid this $30,000 to Burg on April 25, 2019. How much of the salary is taxable to Burg in 2018?

a.$50,000

b.$60,000

c.$65,000

d.$80,000