VMIC Corp. has asked you to look at the following The interest rate is 10%. Year Marginal Cost (Defender) EUAC (Challenger) 1 $2500 $4500 2 2400 3600 3 2300 3000 4 2550 2600 5 2900 2700 6 3400 3500 7 4000 4000 (a) What is the defender's lowest EUAC? (b) What is the challenger's minimum cost life? (c) When, if at all, should we replace the defender with the challenger? Please upload excel table or answer the formula, thanks!