Mary was troubled because she_____.

　　事实细节题。

　　定位到文中第一段的第一至三句，“Mary didn’t know what to send to her grandparents for Christmas. It was always hard to choose a good Christmas present for them. They didn't need much, and it was hard for her to be creative every year.”， 玛丽不知道圣诞节送什么礼物给她的祖父母。给他们选择一个好的圣诞礼物对她来说很难。他们不需要太多，但对Mary来说每年都创新地选择礼物对她来说太难了。故选A。