Suppose you have the instruction Add 900. Given the memory, as follows, the contents of AC and the base register are 200 and 100 respectively.

Memory address value 800 900 900 1000 1000 500 1100 600 1200 800 1300 250

What would be loaded into the AC, if the addressing mode for the operand is:

1. Immediate
2. Direct
3. Indirect
4. Indexed