Colour Grid Rotation: What Comes Next?

Explanation

Each 2x2 colour grid is a 90-degree clockwise rotation of the previous one. Grid 1 has green top-left, yellow top-right, blue bottom-left, red bottom-right. Grid 2 is Grid 1 rotated 90 degrees clockwise. Grid 3 continues that rotation. Applying one more 90-degree clockwise rotation to Grid 3 gives option A: yellow top-left, red top-right, green bottom-left, blue bottom-right.