Consider an instruction Add 1000. Memory contents, Accumulator (AC), and R1 Register contents are depicted in the below figure: (such as memory address 1000 contains a value 1400, memory address 1100 contains a value 400 etc. All the numbers used here are decimals.)

Assuming R1 is implied in the indexed addressing mode, determine the actual value loaded into the accumulator (AC) using the following addressing modes:

1. Immediate

2. Direct

3. Indirect

4. Indexed