Correct option is C
Porosity in welding refers to the presence of small, fine holes or cavities within the weld metal, caused by the entrapment of gas during solidification. These tiny holes are often evenly distributed throughout the weld and can weaken the structural integrity of the weld joint. Porosity is typically caused by contamination, improper shielding gas, or incorrect welding techniques. It is a common defect that must be minimized to ensure the strength and durability of the weld.
