Answer: C. personal power.
Options: A. position power.
B. political power.
C. personal power.
D. connection power.
Explanation: When a person in an organization is seen as a person of authority due to their personal knowledge or skills, the leadership role they hold is due to their personal power. This is what Robert has. Due to his problem solving skills and knowledge of his company's software, his colleagues will naturally seek him out when they have any problem with the software. This creates a sort of leadership role, even if it is an informal one.
It is different from position power, which is the power an individual has solely because of his job title.