How does the named input format work?

The correct option indicates that in named input, values must be specified in the format of variable=value. This means that each value in the data line is explicitly assigned to a variable using the assignment operator "=", which helps SAS understand how to populate the dataset.

This format allows for clarity and precision when reading data, as each variable is clearly defined. For example, if you have a variable called 'age', the input would look like this: "age=30". This method is beneficial, especially when dealing with datasets where the order of the values may not align with the order of the variables in the input statement.

In contrast, named input does not specifically require numeric values, nor does it impose restrictions on character inclusion beyond the requirement of proper syntax. Also, the input format itself must be determined at the start of the data step; while you can specify different input methods within your code, switching between input styles should be done in accordance to the logical flow of the data reading process rather than arbitrarily.