If the workweek rises from forty hours to sixty hours and output increases by ten percent, which factor is essential for assessing welfare?

Correct answer: Lost leisure and work stress

The governing concept is that GDP records market production but does not fully record the costs of producing it. Increasing work time from 40 to 60 hours may raise output by 10%, yet workers lose leisure and may experience greater fatigue or stress. These effects can reduce welfare, so option B is essential. Output alone, export prices, or tax collection cannot provide a complete welfare assessment.