The answer is C: purple hexagon.

The rule
The pattern repeats every 3 things: purple hexagon, purple hexagon, purple star. Then it starts again from the beginning.
The pattern as Python code
Here is a tiny Python program that follows the same rule. Type it into IDLE and run it to print the whole pattern, including the answer.
pattern = ["purple hexagon", "purple hexagon", "purple star"]
for position in range(8):
print(position + 1, pattern[position % len(pattern)])
When you run it, Python prints:
1 purple hexagon 2 purple hexagon 3 purple star 4 purple hexagon 5 purple hexagon 6 purple star 7 purple hexagon 8 purple hexagon
Pixel says: Try changing a number in the code and run it again. Can you make the pattern go on for 20 steps? Meow!