Which of the following people is likely to have the highest required retirement savings rate, if each plans to retire at age 65?

George, who earns $50,000 a year and starts saving for retirement at age 45

Vanessa, who earns $33,000 a year and starts saving for retirement at age 28

Bernard, who earns $15,000 a year and starts saving for retirement at age 20

Celina, who earns $44,000 a year and starts saving for retirement at age 36