Which of the Following Double Entries Will Result in Decreases

Which of the following double entries will result in decreases in expense accounts?
Please select all that apply.

A) Debit trade payables, Credit purchases (double entry to record purchase returns made to suppliers) .
B) Debit prepayments, Credit rent expense (double entry to record rent paid in advance) .
C) Debit cash, Credit irrecoverable debts (double entry to record cash recovered from an insolvent debtor that was previously charged as an expense) .
D) Debit allowance for receivables expense account, Credit allowance for receivables (double entry to record an increase in the allowance for receivables) .