Parent State ID: 46
State Depth: 7
Action Taken: pick-up(block_d)
Action Reasoning: To achieve the goal state, we need to move block D onto block C. Since block D is clear and the hand is empty, we can pick up block D and position it on block C, increasing the alignment with the goal state.
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 not clear. Block D is in the hand and not clear. The hand is not empty.
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)', 'stack(block_b, block_c)', 'pick-up(block_d)']

INACTIVE REASON: action path invalid: The last action, pick-up(block_d), is invalid because block_d is not clear and the hand is not empty, violating the preconditions for the action.
