Concept:An increase in provision for doubtful debts is an additional business expense.
Explanation:Provision for doubtful debts is created for expected losses from credit sales.
When the provision increases, the extra amount is charged to the income statement as an expense.
This added expense reduces the profit earned during the period.
Gross profit is calculated before charging such operating expenses, so it remains unchanged.
Net profit is calculated after deducting all expenses, so it decreases.
Therefore, an increase in this provision leads to a lower net profit.
Answer:B. A decrease in net profit.