When calculating labor costs for striping a parking lot with 300 stalls, a contractor estimates a crew production rate of 50 stalls per hour. How many crew hours are needed for striping?

1. Exactly 3.0 crew hours required for striping.
2. Exactly 4.0 crew hours required for striping.
3. Exactly 5.0 crew hours required for striping.
4. Exactly 6.0 crew hours required for striping.