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

Action Reasoning:
To achieve the goal state, I will place block D on block B, stacking the blocks progressively as needed. This moves us closer to the goal configuration.

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

Action Chosen:
stack(block_d, block_b)
