Parent State ID: 47
State Depth: 7
Action Taken: pick-up(block_d)
Action Reasoning: The goal is to stack blocks in the order: C, D, B, A. Since all blocks are clear and on the table, the first step should be to pick up block D and place it on block C, which aligns with the goal state.
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 in the hand and not clear. The hand is holding block D.
Action Path: ['unstack(block_b, block_c)', 'stack(block_b, block_d)', 'unstack(block_b, block_d)', 'stack(block_b, block_d)', 'unstack(block_b, block_d)', 'put-down(block_b)', 'pick-up(block_d)']

INACTIVE REASON: action path invalid: The last action "pick-up(block_d)" is invalid because the precondition that block_d must be clear is not met. The current state's natural language description and visualization are accurate, but the last action is not logical for achieving the goal state.
