How should a driver properly check the engine oil level (niveau d'huile moteur) using the manual dipstick (jauge d'huile)?

1. Park on level ground with engine switched off and cold (or rested for several minutes), remove dipstick, wipe clean, reinsert fully, withdraw again, and check that oil level is between MIN and MAX marks
2. Check with engine running at high idle speed on a steep slope
3. Check only when the oil pressure warning light illuminates on the dashboard
4. Add oil until it overflows from the dipstick tube