Step 1: Test each option against the purpose of weighting:
If profit is equal every year (A), weighting changes nothing since all years already agree — simple average alone suffices, so weighting serves no purpose there.
Step 2: Isolate the trend case:
Only when successive years differ, and specifically when later years are more indicative of the business's current earning power (an increasing trend), does assigning larger weights to recent years improve the estimate over a plain average.