Attempt Number: 4
Error Message: Action not unique compared to other actions chosen from this state before. Choose a new action

Action Reasoning:
The current state has block `d` in the hand. To progress towards the goal where block `d` is on block `b`, the next logical action is to stack `d` on `b`, as `b` is clear and the hand is currently holding `d`.

New State Description:
Block `a` is on the table and clear. Block `b` is on the table, not clear, and supports block `d`. Block `c` is on the table and clear. Block `d` is on block `b`, clear, and is no longer held by the hand. The hand is empty.

Action Chosen:
stack(d, b)
