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

Action Reasoning:
We need to place block 'd' on top of block 'a'. Since the hand is empty and block 'd' is clear and on the table, we can pick up block 'd' to prepare for stacking it on 'a'.

New State Description:
The hand is holding block 'd'. Block 'a' is on top of block 'c' and is clear. Block 'b' is clear and on the table. Block 'c' is not clear and on the table. Block 'd' is no longer on the table and is not clear. The table supports block 'b', 'c', and nothing else. The hand is no longer empty.

Action Chosen:
pick-up(d)
