Notice how overall Amazons gross profit % trend is increasing while the profit margin trend is decreasing.

	2009	2010	2011	2012
Gross Profit Margin	22.57%	22.35%	22.44%	24.75%
Profit Margin	3.68%	3.37%	1.31%	(0.06)%

Which of the following is a reasonable explanation for the inverse trends?

Higher demand has allowed Amazon to increase their prices, while higher overhead expenses have been hurting overall profits.

Amazon issued new stock during the year to raise additional capital.

Inventory prices have increased resulting in increased COGS.

Please help with the answer and an explanation of it.