Given the benefits and costs schedule shown below for projects A, B, and C determine which project is best from an economic efficiency point of view. Conduci the assessment for discount rates of 8 percent, 10 percent, and 12 per- cent. How docs the discount rate affect the choice of the "best" project? 4. Expected yearly cost Expected yearly bencfil Year $30 10 10 $10 $0 20 20 l0 10 50 $0 l0 10 10 10 30 15 10 10 10 10 10 10