Final answer:
The primary advantage of Analytics with Cassandra is its distributed storage capability, providing high availability and fault tolerance for handling large data sets.
Step-by-step explanation:
The best advantage of Analytics with Cassandra is c) Distributed storage. Cassandra is well-known for its robust distributed architecture, which allows it to handle large amounts of data across multiple servers. This feature ensures high availability and fault tolerance. Options such as real-time processing and predictive analysis are capabilities that can be built on top of Cassandra using additional tools and software, but these are not inherent advantages of Cassandra itself. The schema-less data model is a feature of Cassandra but not specifically an advantage for analytics over its distributed nature.