Step 1: Observe the given sequence in the question — each figure contains a circle inside a square with lines drawn inside the circle.
Step 2: The pattern shows that as we move from left to right:
- The number of lines inside the circle decreases by one in each step.
- The orientation of the lines alternates between two sets: diagonal and straight.
Step 3: In the first figure, there are many diagonal lines.
Step 4: In the second figure, fewer lines remain.
Step 5: In the third figure, even fewer lines are present.
Step 6: Following this logic, the fourth figure must have a further reduced number of lines, consistent with option (C).
Thus, the missing figure is $\mathbf(C)$.