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

There are six positions round the circle. From figure 1 to figure 2, the top and bottom symbols swap (☼ and △), and the other four symbols move one place anticlockwise (upper-right → upper-left → lower-left → lower-right → upper-right). Applying this to figure 2 gives ☼ at the top and △ at the bottom, with □ upper-right, ○ lower-right, ◇ lower-left and ● upper-left, which is option C. Applying the rule once more gives figure 4, which confirms it.