Parent State ID: 25
State Depth: 8
Action Taken: put-down(d)
Action Reasoning: Since block `b` needs to be clear to place block `d` on it, I will put down block `d`. This will clear the hand and position block `d` for future stacking.
State Description: Block `a` is on the table and clear. Block `b` is on the table and clear. Block `c` is on the table and clear. Block `d` is on the table and clear. The hand is empty and no longer holding anything.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'put-down(a)', 'unstack(c, b)', 'put-down(c)', 'pick-up(d)', 'put-down(d)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: Action does not align with the goal state where block_d should be on block_b.
