auto-increment addressing mode

Question

Which of the following is/are true of the auto-increment addressing mode?

I.  It is useful in creating self-relocating code.
II. If it is included in an Instruction Set Architecture, 
    then an additional ALU is required for effective address 
    calculation.
III.The amount of increment depends on the size of the data
     item accessed.

Answer 1

The amount of increment depends on the size of the data item accessed.

Answer 2

If it is included in an Instruction Set Architecture, 
    then an additional ALU is required for effective address 
    calculation.

Answer 3

for self relocating code the code can be move to any adress location so there is nothing with auto increment addressing modes.
in auto increment after data is accessed from the position then it is increment by step size therfore it depends on the size of data items to be acessed.
therefore option c is correct