For the following alternatives, answer the questions below. [8] Incremental B/C when PW of compared with Alternative B/C Ratio alternative Disbenefits, Costs, $ Benefits, $ ] K L M $ 20 22 4 0.90 1.57 2.00 K 23 28 5 a d 2.50 L 27 35 6 1.07 0.50 M 25 b 2 1.12 1. Determine the values of the letters a, b, c and d and show your calculations. [4]