Its your 20th birthday and you have decided that on each of your next 40 birthdays you will contribute $6,000 to a Roth IRA account. If you earn an 8% annual rate of return both before and after your retirement at age 60, how much annual retirement income will your IRA provide for you during your first 35 years of retirement?

a. 123,488

b.133,367

c. 1678686

d.1554,339

Please help me answer this question manually using a formula. Thanks