Labor productivity measures output per unit of labor input

Steps:

• Define labor productivity as cakes produced per labor hour: cakes ÷ labor hours.
• Calculate for A: 40 cakes ÷ 10 hours = 4 cakes/hour.
• Calculate for B: 640 cakes ÷ 40 hours = 16 cakes/hour.
• Calculate for C: 750 cakes ÷ 50 hours = 15 cakes/hour; for D: 500 cakes ÷ 100 hours = 5 cakes/hour.

Why B is correct:

• B yields the highest productivity (16 cakes/hour) using the formula output per input.

Why the others are wrong:

• A: Lowest productivity at 4 cakes/hour.
• C: Productivity of 15 cakes/hour, below B's 16.
• D: Productivity of 5 cakes/hour, far below B.

Final answer: B