Common sense in a sentence (about music)!

Using the phrase "common sense" in a sentence: 

It is common sense to keep your instrument out of the rain.

It is common sense that there are many different genres of music.

It is common sense that music is sound.

Using some plain old "common sense" in a sentence:

 If you want to play a trumpet you need to blow through it.

You need ears to hear music.

Ithink the answer is b