A:1∶40000
B:1∶400000
C:1∶4000000
如图,在▱ABCD中,AE、BF分别平分∠DAB和∠ABC,交CD于点E、F,AE、BF相交于点M.
若△ABC∽△A′B′C′,其面积比为1:2,则△ABC与△A′B′C′的相似比为( )