What does the aircraft do when lift equals weight in stabilized level flight?

1. 1It starts a slow steady climb
2. 2It starts a slow steady descent
3. 3It is at the critical angle of attack
4. 4It stays in vertical equilibrium

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 5: Aerodynamics of Flight — Weight, page 105