You have two options for saving for retirement. You could deposit $300 today in a retirement account, and then continue to deposit $300 at the beginning of every month, and earn a 7% return, compounded monthly. Or you could wait 20 years and deposit $1,100 at the end of the month and earn a 9% return, compounded monthly. You will retire in 40 years no matter which option you choose. Which option will generate a larger retirement balance when you retire at the end of the month 40 years from now