Step 1: Maximum Power Transfer Theorem Application.
The Maximum Power Transfer Theorem dictates that maximum power is delivered to the load when the load resistance (\( R_L \)) equals the Thevenin equivalent resistance (\( R_T \)) as observed from the load's terminals.
Step 2: Summary.
In summary, maximum power transfer occurs when the load resistance matches the Thevenin equivalent resistance.
Final Answer: \[\boxed{(2) \, \text{Thevenin's equivalent resistance } (R_T)}\]