Which three of the sentences use slang? Hey, what’s up? Thank you very much. I’m just going to chill today. That’s a sweet thing to say. Drew got busted.

Hey, what's up?

"What's up" can be considered to be slang.

Thank you very much.

This sentence does not use slang; it is a very professional sentence.

I'm just going to chill today.

The word "chill" is slang.

That's a sweet thing to say.

This sentence does not contain any slang words.

Drew got busted.

"Busted" is a slang word.

Therefore, the 3 sentences with slang are:

Hey, what's up, I'm just going to chill today and Drew got busted.

A,B

Explanation: