Answer:
The answer is "increase; LRAS curve to the right".
Explanation:
The curve LRAS represents the flow between all the level of wages and economic GDP supplied because all prices are fully flexible, also with nominal salaries; its cost may change all along LRAS, however, the output cannot, as it represents the complete output of workers, that's why the several economists say that lower marginal rate consistently increases the motivation to work, shifting the LRAS curve to the left.