Position Independent Code: This code can be placed anywhere in the primary memory, executes properly regardless of its absolute address. This differs from relocatable code which requires a program loader to modify program before execution so it can run from a particular memory location.
Relative Addressing mode is suitable for Program-Independent-Code (PIC) because Effective Address can be calculated by adding displacement to the PC.
# Indexed mode can not be used because Base Address is provided in the instructions itself. Whenever position of code changes, address in all instructions needs to be changed. However, Base Register Mode (BRM) can be used to write position independent code because in BRM base is present in base register while index or offset is present in the instructions.
ANSWER: (C) Relative Mode