What type of data structure can be created using a DATA step?

The correct answer highlights that a DATA step in SAS is used to create derived data sets from existing data. This means you can manipulate or transform pre-existing data into new data sets by applying various operations such as calculations, data filtering, and new variable creation. Within the DATA step, you can also combine data from multiple sources, sort data, or aggregate it, ultimately enriching your analysis.

This versatility allows users to effectively take raw data and tailor it to their specific analytical needs. The DATA step is fundamental to the data manipulation and preparation process in SAS, making it a crucial tool for data analysts.

In contrast, the other options presented focus on more limited or incorrect categorizations of what can be achieved with a DATA step. The mention of matrices and character data sets only overlooks the broader capturing of various data types and structures that can be created. Similarly, asserting that DATA steps can only create static data sets disregards their dynamic capabilities of processing and transforming data.