During an interview if a manager asks you " why did you resign from previous job" what answer would you like to prefer?

Welcome management does not care about its employees and can not work professional and professional

i want to enhance my skills 

If i have three years or more experience , i can answer that i want to increase my experience in your company

If it is less than two years i can  answer like : i couldn't find  myself in this job .

Note : some interviewed employees have no problem with their previous work , but sometimes the bad circumstances force them resign and search for an other work in other location , so this question sometimes unnecessary if the interviewed trained well , experienced , and will be add value for the company    

Looking for a better & challenging opportunity.

I have planned to leave my current job in order to develop my skills in a certain area.