Asound-producing object is moving toward an observer. the sound the observer hears will have a frequency that actually being produced by the object. lower than the same as higher than

A sound-producing object is moving toward an observer. The sound the observer hears will have a frequency  higher than that actually being produced by the object.

This is what i found on google “according to the collision theory, the following criteria must be met in order for a chemical reaction to occur: molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break. molecules must collide with the proper orientation.” i hope this information you.

I'm pretty sure the answer is c