Which statement best describes the INPUT statement in SAS?

The INPUT statement in SAS plays a crucial role in data reading and importing processes. It is primarily used to define how data should be read into SAS from external sources, which can include raw data files or user-defined data. This statement tells SAS whether to expect numeric, character, or other types of data and how to interpret this data when importing it into a SAS dataset.

Typically, when reading data, the INPUT statement specifies the variable names, their order, and informs SAS about the format of the incoming data. This allows it to properly assign the data to the corresponding variables as it reads through the input file. Therefore, option A correctly captures the main purpose of the INPUT statement in SAS, which is focused on the reading of data rather than formatting or later processing.

For context, the other choices focus on different aspects of data manipulation in SAS. For example, formatting output or specifying variable types pertains more to different statements or procedures in the language, but they do not directly describe the essential function of the INPUT statement itself.