The asset Cash will be credited because you are decreasing an Asset, Advertising Expense will be debited because you are increasing an expense.

The following acocunts have a normal debit balance:
Expenses, Assets, and Dividends
A Debit will increase the account balance and a Credit will decrease the account balance.

The following accounts have normal Credit Balance:
Unearned Revenues, Revenues, Liabilities, and Owners Equity accounts
A Debit will decrease these accounts, while a Credit will increase these accounts.