Sally receives $300 each month for sick pay during her three months of sick leave. What amount must she report as income on her tax return?

Sally must report the total amount of sick pay received during her three months of sick leave as income on her tax return. Since she receives $300 each month, the total amount for the three months is calculated by multiplying the monthly payment by the number of months: $300 x 3 = $900. This means that the correct total for the sick pay is $900, which must be reported as income.

Given the choices, the correct amount to report as income is indeed $900. Hence, option D accurately represents the total income from sick pay Sally received during her sick leave period.