Final answer:
The coordinates of the point after being reflected across the x-axis are (-2, -6), so the correct answer is d. (-2, -6).
Step-by-step explanation:
The original coordinates of the point are (-2, 6). When a point is reflected across the x-axis, its x-coordinate remains the same, but the y-coordinate is negated. Therefore, the reflected point across the x-axis would have coordinates (-2, -6). The x-coordinate remains -2 because the point does not move horizontally, while the y-coordinate changes from positive to negative, which reflects a move across the x-axis in a vertical direction but staying at the same horizontal position.