need help with this question

Semi-Goods Inc. requires a minimum rate of return of 13.5% on investment proposals. There are currently two proposals considered, but only one may be chosen. The first investment alternative, Alternative A provides a net return of $3500 per year for 10 years. The second Alternative, Alternative B provides a net 1 return of $9500 for years 3,6 and 8 . Determine the preferred alternative using the discounted cash flow criterion. (6 marks)