Coat Closet's gross profit margin last year was 22.4% and this year it has fallen to 20.5%. This decline in the gross profit margin could be explained by all of the following EXCEPT the store had to pay higher prices to suppliers than it passed on to customers. there was a general decline in gross profit margin in the whole industry. inventory prices were higher without a corresponding increase in selling prices. the store lowered its selling prices and had more "bargain days