To determine which figure comes next in the sequence, we must first analyze the pattern shown in figures I, II, and III:

1. The shaded area of each circle is rotating clockwise by 90 degrees from one figure to the next.
2. In figure I, the shaded area is a quarter of the circle at the top.
3. In figure II, the shaded area is a quarter of the circle, rotated 90 degrees clockwise, now in the right section.
4. In figure III, the shaded area rotates another 90 degrees clockwise, covering the bottom half of the circle.

Following this pattern, in figure IV, the shaded area should rotate an additional 90 degrees clockwise to cover the left half of the circle. This gives us the correct answer.

Thus, the correct option for figure IV in the sequence is the image with the shaded left half.