Concept:Real wages rise when workers produce more per hour, allowing firms to pay higher wages without causing inflation.
Explanation:An increase in productivity means each worker creates more output in the same time.
As productivity grows, a firm earns more revenue from each worker.
This extra revenue can be shared with workers through higher wages, without raising product prices.
Higher productivity therefore supports a sustained increase in real wages.
In contrast, more labour quantity, service-sector job contraction, or rising capital costs do not directly improve the real value of wages.
Answer:A. an increase in the rate of productivity