Which of the follow could explain why the price of a grande latter at a Starbucks in San Diego violates purchasing power parity compared to a latte in Tijuana?

	A). The price of real estate in San Diego is much higher than in Tijuana.
	B). There is an impenetrable wall along the US-Mexico border.
	C). Mexican-run businesses offer a level of hospitality that is incomparable to other countries.
	D). All of the above are possible explanations.