For each of the scenario given below analyse which of the listed tools$/$technology would you use and the approach you will follow to have an efficient scalable system Elucidate the reason for your choice. List out the pros and cons $($if any$)$ for your choice as well.

$[$Note: You can propose an approach with other tools$/$technology$,$ not in the listing as well, but with proper justification.$][6$ Marks$]$

a$)$ Imagine an online retailer wants to collect customer reviews from their social media pages and transport them to a Hadoop$-$based data warehouse for detailed sentiment analysis and archival. To achieve this, which technology would be most suitable: Apache Kafka, Apache Spark, or RabbitMQ?

b$)$ Consider a high$-$frequency trading platform that needs to handle incoming trade requests with immediate responses to clients. However, these requests also require further processing by a complex algorithm that could take longer to complete. To manage this situation, would you prefer using Apache Kafka or RabbitMQ?