Parent State ID: 1
State Depth: 2
Action Taken: stack(blockD, blockC)
Action Reasoning: To achieve the goal state, block D needs to be placed on block C first. Since block D is already held, the best next action is to stack block D on block C.
State Description: Block A is on the table and clear. Block B is on block C and clear. Block C is on the table and supports block B. Block D is on block C and not clear. The hand is empty.
Action Path: ['pick-up(blockD)', 'stack(blockD, blockC)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: Block C is not clear, making the stack action invalid.
