Final answer:
The forward slash (/) in an INPUT statement signals the program to load the next record in the input buffer, crucial for handling multi-line data input, the correct option is C).
Step-by-step explanation:
When used in an INPUT statement, a forward slash (/) indicates option c. Load the next record in the input buffer. This character is used as a pointer in data step programming to mark the transition to a new row or line of data.
Understanding the functionality of the forward slash in an INPUT statement is crucial for managing data input in programs. For example, if you have a dataset where multiple lines of data should be read for one observation, the forward slash helps the program know when to proceed to the next observation.