Final answer:
Marilyn must recognize $200 as income this year to minimize her tax burden.
Step-by-step explanation:
Marilyn must recognize income based on the percentage of services rendered during the current year. Since she received a prepayment of $4,000 for child care services to be rendered evenly over the next 20 months, she must recognize 1/20th (or 5%) of the prepayment as income in the current year.
Therefore, Marilyn must recognize $200 ($4,000 x 5%) as income this year to minimize her tax burden.