Attempt Number: 4
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 'd' needs to be on top of block 'c'. Since both blocks 'c' and 'd' are clear and on the table, the next step is to pick up block 'd'.

New State Description:
Block 'a' is on top of block 'b'. Block 'b' is on the table and supporting block 'a'. Block 'c' is on the table and clear. Block 'd' is held by the hand. The hand is not empty.

Action Chosen:
pick-up(d)
