Ken Was Recently Fired from His First Job as a Nursing

Ken was recently fired from his first job as a nursing assistant for failing to meet performance standards. When he applies for another job, what should he do if he is asked why he left his last job?

A) Try to change the subject and emphasize his nursing assistant skills.
B) Say that he quit voluntarily.
C) Tell the truth and explain what he has done to learn from his mistake.
D) Politely let the interviewer know that the question is illegal.