"because you told me”, “…told me to" or “…told me so"?

Question

Could you tell me which one of the following sentences is the most correct and natural?

I quit smoking because you told me.

I quit smoking because you told me to

I quit smoking because you told me so.

Answer 1

You tell someone to do something. You told me so means something different.

I know smoking is bad for me because you told me so.

Answer 2

The OP's second option is best because when the meaning is clear, the infinitival marker "to" can stand alone to create an elliptical construction, which allows the speaker to avoid repeating the same phrase twice. For example,

I know I should [eat healthy foods like fruit and vegetables, and exercise more], but I just don’t want to.

• I quit smoking because you told me to [stop/quit smoking].

The third option is a bit strange because the meaning is different:

• I quit smoking because you told me so.

This is usually reserved for when someone predicts something which you disagree with, for example, “Kanye West will win the US presidential election”. If the prediction (or warning) comes true and Kanye West is elected the president of the USA, the prognosticator can announce–“I told you so!”

I told you so

used when you have warned someone about a possible danger that has now happened and they have ignored your warning (Longman Dictionary)

• If she failed, her mother would say, 'I told you so.'

Answer 3

“I quit smoking because you told me to do so”
would be correct.