Concept:The management’s decision is a direct response to the high demand and shortage of stock observed during the fair.
Explanation:The passage clearly states that the fair received unexpectedly high customer demand in its initial days.
Many popular titles were exhausted very quickly, leading to long queues and repeated customer requests for restocking.
This indicates that a large number of customers could not purchase the desired materials because the books went out of stock early.
To address this unmet demand, the management extended the fair for four additional days and arranged emergency stock transfers from nearby warehouses to selected outlets.
The other options are not supported by the statement: there is no mention of permanent price reduction, closing outlets, low customer response, or testing a new billing system.
Hence, the most probable reason behind the extension is the inability of many customers to buy due to early stock exhaustion.
Answer:Option B: A large number of customers could not purchase desired materials because several books went out of stock early.