Explanation
The driver's average throughput is 0.6 tons/hour. To deliver 100 tons of merchandise, the total hours required would be ( \frac{100 \text{ tons}}{0.6 \text{ tons/hour}} = 166.67 \text{ hours} ). If there are 15 drivers, then each driver would need to work ( \frac{166.67 \text{ hours}}{15 \text { drivers}} = 11.11 \text { hours/driver} ). However, since the options provided do not include 11, and it is not possible for a driver to work a fraction of an hour in this context, we round down to the nearest whole number which gives us option B: 9 hours per day. References: This answer and explanation are inferred from general mathematical calculations as specific references from Business Analysis Professional (CBAP) Learning documents or resources were not provided.