just B please!!!

math help needed. thank you!

Question 4. I am trying to start saving for retirement. I am investing all my cash into the S&P 500, which we will assume consistently makes 9.8% interest, compounded annually (this is the average return over the past 90 years!). I initially put a lump sum of $100 into my account, and I will depost $10 every second week. (a) After 10 years, how much money will I have invested (i.e. how much money have I spent')? [1] (6) After 10 years, if I sold all of my stocks, how much money will I have in my account? [2] (c) After 25 years, how much money have I invested (again, 'spent')? (d) If I had not sold my stocks at the 10 year mark and instead held onto them an additional 15 years before selling, how much additional money would I have in my account (2)