A blue triangle and an orange circle change position along the series. Two different changes take turns. Which figure comes next?

The changes alternate: a quarter turn $(90^{\circ })$ clockwise, then a flip in an upright mirror (left and right swap), then a quarter turn again, then a flip. The last change was a flip, so now the figure turns $90^{\circ }$ clockwise: the triangle's right angle moves to the top-left corner and the circle to the bottom-right, (b). (Check: the pattern repeats every four steps — the 5th figure equals the 1st — so the 6th must equal the 2nd.) (a) flips again (giving back the fourth figure), (c) turns anticlockwise and (d) turns and flips.