题目选项分析

In 1999, America Mart, which previously only sold through retail outlets, began selling on the internet while keeping its retail stores open. Total sales increased in 1999, but profits were less than in 1998.

Which of the following, if true, contributes most to explaining why America Mart's profits were more in 1998 than in 1999?

【选项】The increase in costs due to setting up the web site in 1999 was greater than the increase in revenue from sales in 1999.