Which base of power is defined as expertise based on knowledge in a field?

• A. Expert power
• B. Legitimate power
• C. Referent power
• D. Informational power

Answer: (A)

Expert power arises from others' belief that you have specialized knowledge in a particular area. When people see you as an authority in a field, your judgments and advice carry more weight because of that demonstrated competence and expertise. This is different from legitimate power, which comes from holding a formal position or title; referent power, which stems from personal charisma and the desire to be associated with you; and informational power, which comes from having access to specific information you can share. In contexts where knowledge and skill define influence, expert power is the best fit because it centers on credible expertise in a domain.