The correct answer is 3 . Non-destructive testing qualification systems typically recognize three levels of competence: Level 1, Level 2, and Level 3. Level 1 personnel generally perform tests under instruction and record results. Level 2 personnel normally select techniques, perform tests, interpret results, and prepare reports within the applicable method and standard. Level 3 personnel normally have the highest responsibility, including procedure development, method selection, technical oversight, training, and examination responsibilities. Option A is incorrect because four levels is not the typical NDT certification-level structure, although some employer programs may separately recognize trainee status before Level 1. Option C is also incorrect because two levels would omit the senior technical authority level required for oversight and governance. In CRL Asset Condition Management, certification levels matter because condition-monitoring results must be produced and interpreted by competent personnel. The International Committee for NDT explains that ISO 9712-based qualification defines three levels: Levels 1, 2, and 3.