Attempt Number: 2
Error Message: Action not unique compared to other actions chosen from this state before. Choose a new action

Action Reasoning:
Block D is currently in the hand and Block C is on the table and clear. The next action to get closer to the goal state is to stack Block D on Block C.

New 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 not clear, as Block D is now on it. Block D is on Block C and clear. The hand is empty.

Action Chosen:
stack(block_d, block_c)
