Answer:
c. debit to Bad Debt Expense for $3960.
Explanation:
The journal entry to record the bad debt expense is shown below;
Bad debt expense Dr ($3,140 + $820) $3,960
To Allowance for doubtful debts $3,960
(Being the bad debt expense is recorded)
For recording this we debited the bad debt expense as it increased the expenses and credited the allowance for doubtful debts as it decreased the assets
Therefore option c is correct