Explanation/Reference:
Polling, using a reliable-one-way message, and using a SOA Service is a good solution.
Incorrect answers:
A, D: The publish-and-subscribe communication pattern is used when a single message is of interest to multiple consumers. Here there is a single consumer.
E: This is a low level solution that would only be possible if the WMS application could access the database of the PS application.
Note: Over the years there have been many different approaches used to integrate applications. Some of the approaches that proved to be particularly prevalent and successful have become known as integration patterns. There are entire books written on the different types of integration patterns.
There are some patterns that are so common and so foundational that any integration architecture must support them.
A) Message Exchange Patterns
Message exchange patterns describe the order and sequence of messages passing between a service consumer and a service provider. The foundational message exchange patterns that the architecture must support include A1) One-way
A2) Reliable one-way
A3) Request-Response
A4) Request Optional-Respons
B) Synchronous Communications
C) Asynchronous Communications
C1) Bridging Synchronous and Asynchronous
C2) Store and Forward
D) Publish and Subscribe
E) Polling
Reference: Oracle Reference Architecture, Service-Oriented Integration, Release 3.0