Final answer:
In Apache Cassandra, 'Describe commands' is the correct command to list all available operations within the CQL shell. This command is essential for database administrators and developers to understand and interact with the database.
Step-by-step explanation:
The command to list all the available commands and operations in Apache Cassandra is c) Describe commands. This command can be executed within the Cassandra Query Language (CQL) shell to display all the commands that the shell can execute along with a brief description for each. Cassandra is a NoSQL database known for its scalability and high availability without compromising performance. Thus, knowing how to interact with the database, and what commands are available, is crucial for database administrators and developers working with Cassandra.