The answer is B: pink circle.

The rule
The pattern repeats every 3 things: pink circle, pink circle, orange circle. 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 = ["pink circle", "pink circle", "orange circle"]
for position in range(8):
print(position + 1, pattern[position % len(pattern)])
When you run it, Python prints:
1 pink circle 2 pink circle 3 orange circle 4 pink circle 5 pink circle 6 orange circle 7 pink circle 8 pink circle
Pixel says: Try changing a number in the code and run it again. Can you make the pattern go on for 20 steps? Meow!