题目内容：

[单选题]There are two character strings：s and t.s="My favor is computer"，t=substr(s，9，5)．Then the result after operation is

A．S="My favor is computer"； t="compu"；

B．S="My favor is computer"； t="is co"；

C．S="My favor"； t="is co"；

D．S="My favor"； t="is computer"；