Which of the following actions can result in being guilty of unprofessional conduct as a licensed plumber?

Practicing fraud in obtaining a license is a serious violation that reflects a lack of integrity and honesty, which are fundamental ethical standards required in the plumbing profession. This action undermines the trust placed in licensed professionals by the public and the regulatory bodies overseeing the industry. Licenses are granted based on qualifications that ensure professionals meet standards for safety, skill, and ethics. Fraudulently obtaining a license not only endangers public safety but also can lead to significant penalties, including revocation of the license, fines, and possibly criminal charges.

In contrast, providing discounts to customers is a common practice that can be seen as a competitive strategy rather than unprofessional conduct. Being late to appointments, while not ideal, does not necessarily equate to unprofessional conduct unless it becomes a pattern that significantly impacts client relationships. Engaging in networking activities is generally encouraged as it helps build professional connections and can lead to business opportunities. Thus, the act of practicing fraud in obtaining a license stands out as a clear instance of unprofessional conduct that has widespread implications for both the individual and the profession as a whole.