Final answer:
The demand for labor increases when the price of another resource increases, as long as the need to produce more due to higher prices (output effect) is greater than the desire to use less of the expensive resource (substitution effect).
Step-by-step explanation:
The correct option that can be predicted to increase the demand for labor is d. An increase in the price of another resource, provided the output effect exceeds the substitution effect.
When the price of a substitute for labor increases, it makes labor relatively cheaper, so employers may prefer to hire more labor instead of using the now more expensive substitute. This situation would lead to a higher demand for labor. Meanwhile, an increase in the price of a pure complement to labor implies that the cost of production overall goes up, which could reduce the amount of labor demanded since employers might produce less. A decrease in product demand naturally leads to a reduction in the need for labor, as less production is necessary. Finally, if the price of another resource increases but the output effect (the need to produce more of the good due to higher prices) exceeds the substitution effect (the desire to use less of the now more expensive resource), firms will demand more labor to increase production, leading to an increase in labor demand.