单项选择题

Sigmund Freud was a world-famous doctor of Vienna(维也纳).Hewas also a man full of humour(幽默). Once, at his 70th birthday party, a friend asked Freud if he could put his work into several words."Well,"saidFreud, "we take the sick out of their trouble and return them to the common suffering." As a devoted ( 忠实的) son, Freud often visited his old mother.Hismother usually spent her summers in asmall mountain town in Austria(奥地利).TheKing Josef usually spent his summers there, too.Oneday in thesummer, a band( 乐队)wasplaying a lively tune( 曲子)whenFreud’s mother was sitting at the window and watc-hing the people singing and dancing on Main Street.Theold woman had a poor memory.Sheheard the band playing, but forgot it was the King’ s birthday.Freudwas visiting his mother on her 95th birthday.Hetold his mother,"Mama, the band is playing for your birthday."She believed him and had a wonderful day. Freud’ s mother felt very happy on her 95th birthday because ______.

A.the King Josef himself came to celebrate( 庆贺)her birthday
B.the people of the town came out to celebrate her birthday
C.she believed that the band was playing for her birthday