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 `a` onto block `d` since block `a` is already in the hand and block `d` is clear and on the table.

New State Description:
Block `a` is on block `d` and clear. Block `d` is on the table and supports block `a`. Block `b` is on the table supporting block `c`. Block `c` is on block `b` and clear. The hand is empty.

Action Chosen:
stack(a d)
