Attempt Number: 2
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, block 'c' needs to be on the table. Since block 'c' is currently on block 'd' and clear, we can unstack 'c' from 'd' to start rearranging the blocks.

New State Description:
The hand is holding block 'c'. Block 'd' is clear and on top of block 'a'. Block 'a' is on the table. Block 'b' is on the table and clear. Block 'c' is no longer clear or on block 'd'.

Action Chosen:
unstack(c, d)
