Parent State ID: 22
State Depth: 5
Action Taken: pick-up(block_d)
Action Reasoning: To progress toward the goal state, we need to stack block D onto block C. Currently, block C is clear and on the table, satisfying the requirements for this move. We shall first pick up block D to achieve this.
State Description: Block A is on the table and is clear. Block B remains on block D and is clear. Block C is clear and on the table. Block D is currently held in the hand and is no longer on the table. The hand is not empty.
Action Path: ['unstack(block_b, block_c)', 'stack(block_b, block_d)', 'pick-up(block_a)', 'put-down(block_a)', 'pick-up(block_d)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: Block D is not clear, violating the precondition for pick-up.
