Employment at will is a common$-$law doctrine holding that $\_\_\_\_\_\_\_\_\_\_.$

Question $22$ options:

an employee must provide a minimum of two weeks' notice before quitting a job

employees can be asked to leave a company only if they are willing to do so

employees are free agents, but employers must have a just cause for terminating them

an employer has the right to hire, fire, demote, or promote whomever it chooses