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, we need to place block 'd' on block 'c', which is clear. The next step is to stack 'd' on 'c'.

New State Description:
Block 'a' is on the table and clear. Block 'c' is on top of block 'b' and supporting, with block 'd' on top of it and clear. Block 'b' is on the table. The hand is empty.

Action Chosen:
stack(d, c)
