Correct option is D
Spatter: This refers to small droplets of molten metal that are ejected from the weld pool during welding and can stick to surrounding surfaces, causing surface irregularities.
Burn-through: This is a welding defect where the molten metal completely penetrates the base material, creating a hole.
Underfill: This occurs when the weld metal does not fully fill the joint gap, leaving an incomplete weld.
Slag inclusions: These are solid particles of non-metal (slag) that become trapped within the weld metal, affecting its strength and quality.
