阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。
Sam is an American middle school student. He is studying in Grade 7. He usually gets up at 7:00 o'clock in the morning. But today he gets up at 6:30a.m.and goes to buy a big birthday cake.After that he goes back home and helps his grandparents clean their room. Because it is his grandpa's 80th birthday.
Sam goes to the shop and buys two CDs about Beijing Opera(京剧) for his grandpa. Because his grandpa likes listening to Beijing Opera.
When Sam gets home at noon, his mother is making lunch. His grandpa is drinking tea and listening to Beijing Opera.
Sam says, “Happy birthday to you, grandpa.” Then he cuts the big cake and gives grandpa a biggest piece. Grandpa is very happy and eats it.
In the evening, Sam watches TV with his grandparents together. He is a little tired but very happy, because he can make his grandparents happy.