Find the missing figure in the diagram given below.

To identify the missing figure, let's analyze the progression of the shaded area within the circles.

Step-by-Step Analysis
Observe the Pattern:

First Figure: The circle is 1/4 shaded.

Second Figure: The circle is 2/4 (or 1/2) shaded.

Third Figure (?): Following the pattern of increasing the shaded area by 1/4 each time, this should be 3/4 shaded.

Fourth Figure: The circle is 4/4 (fully) shaded.

Determine the Missing Figure:
The pattern is a consistent increase of the shaded portion of the circle by a quarter at each step. Therefore, the missing third figure should have three-quarters of the circle shaded.