Joe's Cross Fit, a calendar-year, accrual-method taxpayer, provides personal training services. (Note: answer is not $1200)

Joe's Cross Fit, a calendar-year, accrual-method taxpayer, provides personal training services. On December 1, 2016, Barbie pays Joe's Cross Fit $2,400 cash for 24 months of personal training services ($100/month). Barbie's training sessions beginning on December 1, 2016. How much of the $2,400 must Joe's Cross Fit include itn income in 2017