8. Calculation Problem (8 points): You have $100 to invest 4 projects during the future 5 years. The details of the 5 projects are shown as follows: Project A: You can invest at the beginning of every year; Your money can not be redeemed until 2 years later; You can get the principal and interest at the end of the 2 years, totally 120% return. Project B: You can invest at the beginning of every year; Your money can not be redeemed until 3 years later; You can get the principal and interest at the end of the 3 years, totally 130% return. Project C: You can invest at the beginning of every year; Your money can not be redeemed until 4 years later; You can get the principal and interest at the end of the 4 years, totally 140%. Project D: You can government bonds at the beginning of every year; Your money can not be redeemed until 1 year later; You can get the principal and interest at the end of the year, totally 105%. Please build a model to maximize the capital (principal+interest) at the end of the 5 years, and use Excel to find the solution of the model