Answer:
a. an employer has the right to hire, fire, demote, or promote whomever it chooses
Explanation:
Employment-at-will refers to a type of contract in which the employer can fire an employee for any reason; it won't have to establish a just cause to do it. Also, the employer can fire the employee without notice but the reason for the termination can't be illegal like firing someone because of religion. According to this, employment-at-will is a common-law doctrine holding that an employer has the right to hire, fire, demote, or promote whomever it chooses.