In response to the recent housing crisis, the U.S. Consumer Financial Protection Bureau has instituted new rules that all mortgage lenders must follow when processing and issuing mortgages. Doing so has required many mortgage lenders to upgrade or completely overhaul their computer systems to comply with the new rules. Suppose that one lender, Quacken Loans, has been preparing for the new regulations and their management estimated that overhauling their computer system will cost a total of $8M over four years. Three years in, they have already spend $5M on the systems upgrade when they are approached by an outside vendor who has developed a system that can easily bring Quacken into compliance, will cost only $4M, will only take one year to implement, and will bring additional process improvement benefits. What should Quacken Loans do?

(a) They should definitely go with the outside vendor as the new system costs $4M less and will only take 1 year to implement versus 4 years for the internally developed system.

(b) They should go with the outside vendor only if the net additional benefits from the vendor's software are worth at least $5M to Quacken.

(c) They should go with the outside vendor only if the net additional benefits from the vendor's software are worth at least $4M to Quacken.

(d) They should go with the outside vendor only if the net additional benefits from the vendor's software are worth at least $3M to Quacken.

(e) They should go with the outside vendor only if the net additional benefits from the vendor's software are worth at least $1M to Quacken.