Explanation:
For y = x^3 - 4 when x = 0, y = -4.
For y = x^2 + 3 when x = 0, y = 3.
Looking at the graph, the y-intercept of the function is below 0. Hence the bottom part is from x^3 - 4 and the top is from x^2 + 3.
The bottom part has a dark circle, which means when x = 1 it belongs to x^3 - 4.
Hence the answer is D.