Final answer:
The SchemaRDD in Apache Spark is a distributed dataset with a schema, providing structured data processing capabilities.
Step-by-step explanation:
SchemaRDD in Apache Spark RDD refers to c. SchemaRDD is a distributed dataset with a schema in Spark. Contrary to other options, SchemaRDD is not about visualizations, a type of Spark cluster manager, or a storage format. Instead, it represents Resilient Distributed Dataset (RDD) with additional information about the types of data in each column, essentially combining the features of RDDs with those of databases by providing a schema. A schema, in general, is a way to organize information efficiently, allowing for assumptions and structured processing upon activation. In the context of Spark, this translates to easier data manipulation and querying, as if working with structured data in a database.