Look carefully at the sequence of symbols to find the pattern.

Track where each symbol moves from one figure to the next. From figure 1 to figure 2, the symbol at top-left moves to bottom-right, top-right moves to bottom-left, bottom-left moves to top-left and bottom-right moves to top-right. Applying the same movement to figure 2 (△ □ / ● ○) gives ● ○ on top and □ △ at the bottom. Applying it once more gives □ △ / ○ ●, which is exactly figure 4, so the rule is confirmed. The missing figure is option C.