What caused 400 merchandise trailers to show up at the distribution center parking lot?

The correct choice revolves around the complexity and challenges posed by using hundreds of Supply Chain Management (SCM) applications across different platforms. When multiple systems are in play, it can lead to fragmentation and rigidity within the supply chain. This fragmentation often results in inefficiencies, as different platforms may not communicate effectively with one another or may not be aligned in terms of data management and logistics coordination. Consequently, such misalignment can lead to significant operational issues, such as overstocking or understocking, ultimately causing a backlog in the distribution center.

In this context, the arrival of 400 merchandise trailers is indicative of a supply chain disruption where multiple applications are not integrating properly, leading to an inability to process information regarding inventory levels or demand forecasting effectively. This likely resulted in an excess of merchandise being sent to the distribution center unexpectedly, overwhelming its capacity and operations.

While other options touch on issues related to supply chain management, they do not encapsulate the broader implications of using numerous disparate systems, which is the root cause leading to the situation described. Legacy applications, complex supply-chain systems, or lack of real-time reporting capabilities may contribute to problems within a supply chain but do not capture the comprehensive effect of having an excessive number of different applications in play.