Explanation:

GTAW (Gas Tungsten Arc Welding) process does not use consumable electrodes. Let's break down the different welding processes and understand why GTAW is the correct answer.

GMAW (Gas Metal Arc Welding):
- GMAW, also known as MIG (Metal Inert Gas) welding, uses a consumable electrode in the form of a wire.
- The wire is fed through a welding gun, and an electric arc is created between the wire and the workpiece.
- The arc melts the wire, which becomes the filler material for the weld.

Submerged Arc Welding:
- Submerged Arc Welding is a process that uses a consumable electrode in the form of a continuously fed wire.
- The wire is submerged in a granular flux material, which protects the weld from atmospheric contamination.
- The heat generated by an electric arc between the wire and the workpiece melts the wire and the flux, creating a weld.

GTAW (Gas Tungsten Arc Welding):
- GTAW, also known as TIG (Tungsten Inert Gas) welding, does not use a consumable electrode.
- Instead, it uses a non-consumable tungsten electrode to create an electric arc.
- The arc generates intense heat, and a separate filler material in the form of a wire is manually added to the weld pool.

Conclusion:
- Among the given options, GTAW is the only welding process that does not use consumable electrodes.
- GMAW and Submerged Arc Welding both use consumable electrodes in the form of a wire.
- GTAW, on the other hand, uses a non-consumable tungsten electrode, and a separate filler wire is added manually.
- Therefore, the correct answer is option 'B' (GTAW).