A has a line symmetry, you can think of a vertical line going straight through the middle of "A", and the shape is symmetrical about the line. C has a similar line symmetry, except that for C, the line is in the middle and is horizontal.
For B, however, there isn't such a line, as the little "ellipses" (is this the right word? Dunno) aren't of the same size. It also doesn't have a point symmetry, so it has neither of the two types of symmetry
Hope I helped!! xx
