The answer is A: orange circle.

The rule
The pattern repeats every 2 things: orange heart, 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 = ["orange heart", "orange circle"]
for position in range(8):
print(position + 1, pattern[position % len(pattern)])
When you run it, Python prints:
1 orange heart 2 orange circle 3 orange heart 4 orange circle 5 orange heart 6 orange circle 7 orange heart 8 orange 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!