Final answer:
Destructive testing refers to the process of intentionally damaging a component or structure to evaluate its performance or characteristics. In the given options, option D is the correct definition of destructive testing as it involves mechanical testing of a sample or small portion of a weld.
Step-by-step explanation:
Destructive testing refers to the process of intentionally damaging a component or structure to evaluate its performance or characteristics. In the context of the given options, option D is the correct definition of destructive testing. It involves mechanical testing of a sample or small portion of a weld to assess its strength and integrity.