Electric equipment shall be installed in a professional and ___ manner.

• A. Efficient
• B. Safe
• C. Skillful
• D. Orderly

Answer: (C)

The idea here is that electrical work should show capable, quality workmanship. The word that fits best with “professional” is skillful because it directly communicates the installer’s competence and craftsmanship in doing the job correctly, with proper technique and judgment.

Efficiency focuses on speed or cost, which doesn’t guarantee quality. Safety is essential, but the term here is looking for the installer’s demonstrated ability rather than just safety. Orderliness relates to neatness of setup, but it doesn’t inherently express the technician’s level of skill. So skillful best captures the expectation of capable, professional workmanship in electrical installation.