According to the collision theory, which is required for a high number of effective collisions?

High kinetic energy, usually from heat, although more effective collisions could also occur due to the presence of a catalyst, lowering the activation energy required for two atoms to collide and make a product. Generally though, the acceptable answer for this would be kinetic energy caused by an increase in temperature.

D. Molecular collisions with energy to overcome activation energy

About 8 gallons of fuel will be used. (8.08)