Attempt Number: 3
Error Message: Action not unique compared to other actions chosen from this state before. Choose a new action

Action Reasoning:
Block B is currently held by the hand, and we need it on Block D. Therefore, we should stack Block B on Block D to match the goal configuration's sequence.

New State Description:
Block A is on the table and clear. Block B is on block D and clear. Block C is on the table and not clear, with block D stacked on it. Block D is on block C and not clear. The hand is empty.

Action Chosen:
stack(block_b, block_d)
