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

Action Reasoning:
The best next action is to pick up block D, since it needs to be placed on block C in order to start building the target stack.

New State Description:
Block A is on the table and clear. Block B is on the table and clear. Block C is on the table and clear. Block D is in the hand and not clear. The hand is holding block D.

Action Chosen:
pick-up(block_d)
