Study the below given chart carefully to answer the question.
| Temperature | |||||
| Durban | Quito | Columbus | Lisbon | Riyadh | |
| January | 20°C | 15°C | 20°C | 22°C | 35°C |
| February | 21°C | 16°C | 18°C | 20°C | 30°C |
| March | 22°C | 18°C | 16°C | 22°C | 32°C |
| April | 25°C | 20°C | 15°C | 25°C | 36°C |
| May | 28°C | 22°C | 14°C | 18°C | 38°C |
What is the difference between the average temperature of all cities in May and that of February?
1
3°C
2
8°C
3
10°C
4
1°C