The triangle and the circle keep changing sides. Note also how each one changes. Which figure comes next?

At every step the two shapes swap sides, the yellow triangle turns $90^{\circ }$ clockwise (up, right, down, left) and the circle switches between orange and blue. Next: triangle on the left pointing up, orange circle on the right: (d). (b) keeps the circle blue, (c) does not swap sides and (a) turns the triangle the wrong way.