Two kinds of flip take turns along this series: a left-right flip and an upside-down flip. Which figure is the next one?

From box 1 to 2 the figure is flipped left-right, from 2 to 3 upside down, from 3 to 4 left-right again. So box 5 is box 4 flipped upside down: (b). (a) flips left-right twice in a row (it is just box 3 again), (c) is a half turn, and (d) is a quarter turn, which no step uses.