题目

Odland remembers like it was yesterday working in an expensive French restaurant in Denver. The ice cream he was serving fell onto the white dress of a rich and important woman. Thirty years have passed, but Odland can’t get the memory out of his mind, nor the woman’s kind reaction. She was shocked, regained calmness and, in a kind voice, told the young Odland. “It’s OK. It wasn’t your fault.” When she left the restaurant, she also left the future Fortune 500 CEO with a life lesson: You can tell a lot about a person by the way he or she treats the waiter. Odland isn’t the 笔记本每本m元，圆珠笔每支n元，买x本笔记本和y支圆珠笔共需（  ）元.          A、mx+ny；B、（m+n）（x+y）；C、nx+my；D、mn（x+y）.