Final answer:
The correct answer to the question is 'weld joints.' This term refers to the connections between metal parts that have been welded together, which are critical to the structural soundness and mechanical properties of the final fabricated item.
Step-by-step explanation:
Qualified welding procedure is a tested and proven detailed method by which sound weld joints with suitable mechanical properties can be produced. The correct answer to fill in the blank is option b) Weld joints. Welding uses various sources of fuel, including gas, electricity, and laser, to join metal materials through heat and is an essential process in the fabrication of metal components. Through proper welding procedures, sound weld joints that meet specific mechanical and structural requirements can be achieved, ensuring the integrity and safety of the constructed item.