Which of the following reactions is the most exothermic?

1) start temperature = 20°C, end temperature = 65°C
2) start temperature = 20°C, end temperature = 50°C
3) start temperature = 20°C, end temperature = 40°C
4) start temperature = 20°C, end temperature = 25°C

Option 1) start temperature = 20°C, end temperature = 65°C is the most exothermic reaction.