The correct order of increasing acidic strength is:

1. phenol < ethanol < chloroacetic acid < acetic acid
2. ethanol < phenol < chloroacetic acid < acetic acid
3. ethanol < phenol < acetic acid < chloroacetic acid
4. chloroacetic acid < acetic acid < phenol < ethanol

Hint: Acids are more acidic than phenol

Phenol is more stable than alcohol due to formation of more stable conjugate base (resonance stabilized) after removal of H+ from phenol.

On the other hand, carboxylic acid is more acidic than phenol due to formation of more stable conjugate base after removal of  H+ as compared to phenol.


 

Chloroacetic acid is more acidic than acetic acid due to the presence of electron withdrawing chlorine group attached to α-carbon of carboxylic acid.

The overall order is as follows:

Hence, correct choice is (3).