What is the main purpose of a PROC step in SAS?

The main purpose of a PROC step in SAS is to generate reports and manage data, which aligns with the capabilities provided by various PROC procedures. Each PROC procedure is designed to perform specific statistical analysis or data management tasks, such as sorting data, generating descriptive statistics, conducting hypothesis tests, or creating graphical representations of data. For instance, procedures like PROC PRINT create tabular reports, while PROC MEANS provides summary statistics.

While other options mention important functionalities in SAS, they do not encapsulate the main role of a PROC step. Defining global options for a session is accomplished through options statements, writing data to an external file is typically done using a DATA step with the appropriate file references, and reading input data pertains more to the DATA step where data is initially input into the SAS environment. Thus, choice B effectively captures the essence of what PROC steps accomplish within the SAS framework.