问题详情

A
I"m Joe． I-m twelve years old． I like September very much． September 9th is my birthday， and my father"s birthday is in September，too．We have a birthday party ev-ery year． Teachers Day is in September， too． And I can play with all my teachers． So September is my favorite． What about you？
()21．1t is Joe"s________ birthday this year．
A． twelve
B．twelfth
C． ninth
D． nine请帮忙给出正确答案和分析，谢谢！