In which addressing mode is the effective address calculated by adding an offset to a base register value?*DirectIndexedRelativeRegister Indirect

In the context of addressing modes, the scenario you've described involves calculating the effective address by adding an offset to a base register value. This is indicative of the Indexed Addressing Mode. Here's a detailed breakdown:

Explanation of Addressing Modes

1. Direct Addressing Mode: This mode uses the address directly specified in the instruction. There's no offset or register involved.

2. Indexed Addressing Mode: In this mode, the effective address is calculated by adding an index (offset) to a base address held in a register. This allows access to data structures such as arrays efficiently.

3. Relative Addressing Mode: This mode also involves an offset, but it is generally relative to the program counter (PC), not a general-purpose register.

4. Register Indirect Addressing Mode: This mode uses a register to point to the address of the data, but it does not add an offset.

Conclusion

Therefore, the correct option corresponding to your question is Indexed Addressing Mode, as it indeed involves computing the effective address by adding an offset to a base register value.