What are debits and credits? a. A debit is an increase in revenue or a decrease in expenses and a credit is a decrease in revenue and an increase in expenses entry b. Adebit is an increase in shareholders' equity, and a credit is a decrease in shareholders equity cA debit is an increase in a liability or a decrease in an asset, and a credit is an increase in an asset or a decrease in a liability d. A debit is an increase in an asset or a decrease in a liability, and a credit is an increase in a liability and a decrease in an asset