A. Income Statement
Salaries Expense - OVERSTATED
Salaries will be overstated because they would be increased by salaries from January when they should not be as only expenses in February should be apportioned to February.
Net Income - UNDERSTATED
With salaries being higher than they should be, they will reduce the Net income more than they should which will lead to the net income being understated.
B. Balance Sheet
Salaries Payable - No effect
Stockholder's Equity - UNDERSTATED
Net income goes to Equity in the form of Retained earnings. If Net income is understated therefore, so also will Net Income be.