Answer:
A. 100,000
Step-by-step explanation:
Given expression,
Since, when we round only 439,
∵ 439 ≈ 400 ( nearest hundred )
Hence, option 'B' shows a reasonable estimation,
When we round both 439 and 360 to nearest hundred,
That is, 439 ≈ 400, 360 ≈ 400
Hence, option 'C' shows a reasonable estimation,
When we round 360 to nearest hundred and 440 to nearest ten,
That is, 360 ≈ 400, 439 ≈ 440
Hence, option 'D' shows a reasonable estimation.