Which of the following is a legal action that can be taken against a dental hygienist?

Revoking a dental hygienist's license is a legal action that reflects the failure to comply with regulations and standards within the dental profession. This serious measure involves a formal process initiated by the dental board or relevant licensing authority when a hygienist has violated laws, ethical considerations, or professional standards. Such violations may include practicing without a valid license, engaging in fraudulent activities, or committing malpractice.

In contrast, suspending business operations, changing employers, or updating healthcare regulations does not constitute a legal action specifically targeted at an individual hygienist's professional standing. These actions pertain to broader operational or regulatory aspects rather than directly addressing the qualifications or conduct of a dental hygienist. Thus, the revocation of a license is distinctly tied to disciplinary measures against the hygienist as an individual, emphasizing the importance of maintaining ethical and professional conduct within the field.