How should you set transmission before leaving your vehicle parked on a hill?

• Set it in park if your vehicle has automatic transmission system.
• Set it into reverse if parking downhill.
• Set it into first gear if parking uphill.
• All of the above.
  Explanation:

  "When parking on hills, turn your wheels so your car will roll away from traffic or into the curb if it moves. Set the parking brake. For automatic transmissions, put the gear shift in Park. For manual transmissions, shift to Reverse (downhill) or First (uphill). Finally, turn off the vehicle."