Question: Under what condition is the Downlink Power Control procedure **not** allowed to be initiated by the CRNC (Controlling RNC) towards a Node B Communication Context?
Option 1: When another CRNC-initiated dedicated NBAP (Node B Application Part) procedure is ongoing.
Option 2: During handover preparation for the related UE-UTRAN (User Equipment - Universal Terrestrial Radio Access Network) connection.
Option 3: If the Node B Communication Context does not exist.
Option 4: When the CRNC has requested the deletion of the last Radio Link (RL) via this Node B.
Explanation: This is correct because initiating the Downlink Power Control procedure would be contradictory to the request for deleting the last RL, as there would be no links left to adjust power for. Other ongoing procedures or existing contexts do not prevent initiation, and handover preparation is not a mentioned condition affecting this.