The domain of the function f(x)=cos−1(x²−5x+6x²−9)/ log e(x²−3x+2) is
A (−[infinity],1)∪(2,[infinity])
B (2,[infinity])
C [−1/2,1)∪(2,[infinity])
D [−1/2,1)∪(2,[infinity])−{3+√5/2,3−√5/2}