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