Advertising costs as a percentage of sales revenue for soft drink brands with large market shares (such as Coca-Cola and Pepsi-Cola) are lower than for brands with small market shares (Dr. Pepper, Schweppes, Fresca). This is because:A. Big brands can negotiate lower rates with advertising agencies and media ownersB. Advertising campaigns are subject to a large minimum budgets ("indivisibilities")C. Economies of learning—long-established brands such as Coca-Cola and Pepsi have learned how to be more efficient in their advertising campaignsD. None of the above.