Final answer:
For a cash purchase of supplies, record a debit to Supplies to increase supplies and credit Cash to decrease cash on the T-account.
Step-by-step explanation:
If you have a receipt for the purchase of supplies, and you paid for these supplies with cash, the appropriate way to record the transaction in a T-account would be to debit the Supplies account to reflect an increase in supplies, and credit the Cash account to reflect a decrease in cash. This means the correct answer is C: Cash is credited to decrease, and Supplies is debited to increase.