You are at the checkout counter at the local supermarket, use your debit card to pay for your groceries, and select "credit" when the cashier asks "Debit or credit?" Where does the money for this purchase come from?

It got deducted from the checking account directly.

Explanation:

Checking account is the type or kind of bank account, which permit or authorize the easy access or retrieve the funds or money from the bank account of the person.

This account also called as the transactional accounts, it is that account which the person use in order to pay for the bills, make financial transactions.

So, when the person paying for the groceries, has been asked Debit or Credit and by mistake he select the Credit. Therefore, the money or fund is got deducted from the checking account of the person directly.