Final answer:
The direct labor efficiency variance is $1500 unfavorable, but we cannot determine the number of units produced without additional information.
Step-by-step explanation:
The standard for direct labor for product C is three hours at $25 per hour. The direct labor efficiency variance is calculated by multiplying the standard hours by the difference between the standard rate and the actual rate. In this case, the unfavorable direct labor efficiency variance of $1500 indicates that the actual labor hours spent on production exceeded the standard hours by an amount that caused the labor cost to be $1500 more than the expected cost. To determine the number of units produced, we need additional information such as the standard labor hours per unit for product C.
Without this information, we cannot calculate the number of units produced based on the direct labor efficiency variance alone. Therefore, the correct option is D) Unable to tell from data given.