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).