Explanation:

- The "constant sum concept of power" suggests that power is like a fixed pie—if one group gains power, another loses it in equal measure.

- Option 1: Warner—Warner is not known for the constant sum concept of power.

- Option 2: Michels—Robert Michels is famous for the "iron law of oligarchy," not for this specific power concept.

- Option 3: Parsons—Talcott Parsons saw power as something that can expand, not a constant sum.

- Option 4: Weber—Max Weber's theory deals with types of authority and legitimacy, not the constant sum notion.

- The correct answer is Option 2: Michels. He viewed power as a fixed quantity—if some gain, others lose.