设f(x)是定义在R上以6为周期的函数，f(x)在(0，3)内单调递减，且y＝f(x)的图象关于直线x＝3对称，则下面正确的结论是

1. A.
   f(1.5)＜f(3.5)＜f(6.5)
2. B.
   f(3.5)＜f(1.5)＜f(6.5)
3. C.
   f(6.5)＜f(3.5)＜f(1.5)
4. D.
   f(3.5)＜f(6.5)＜f(1.5)

A.f(1.5)＜f(3.5)＜f(6.5)

B.f(3.5)＜f(1.5)＜f(6.5)

C.f(6.5)＜f(3.5)＜f(1.5)

D.f(3.5)＜f(6.5)＜f(1.5)

A.f(1.5)＜f(3.5)＜f(6.5)            B.f(3.5)＜f(1.5)＜f(6.5)

C.f(6.5)＜f(3.5)＜f(1.5)            D.f(3.5)＜f(6.5)＜f(1.5)

（A）f (1.5)< f (3.5)< f (6.5)         （B）f (3.5)< f (1.5)< f (6.5)     

（C）f (6.5)< f (3.5)< f (1.5)         （D）f (3.5)< f (6.5)< f (1.5)