The cost of supplies used during the accounting period is.
I have 2 choices:
a. Accounts payable, debit; supplies expenses,credit
b. Supplies Expense, debit; Supplies, credit.

Which one is correct... please answer??

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We aren't here just to do your work for you. At least show us an attempt to answer the question. Think about what it says: cost of supplies used. Which entry seems more logical? Or maybe more to the point, which ones seems least logical?