Final answer:
To estimate the contour interval from the given elevations, we identify the smallest elevation difference, approximately 1,000 ft. This indicates the best estimate for a contour interval is about 500 ft from the provided options.
Step-by-step explanation:
The question asks for a good estimate of the contour interval based on given elevations. To find a contour interval, we look for the vertical distance between contour lines on a topographic map. Given the elevations presented in the question, such as 10,000 ft, 5,000 ft, 2,000 ft, and 1,000 ft, we should determine the smallest difference in elevation, which seems to be approximately 1,000 ft. This suggests that none of the given elevation changes are smaller than 1,000 ft. Hence, the closest estimate from the options provided would be (D) about 500 ft, as it is the largest possible interval that is less than the smallest difference in elevation we observe.