Two roadway designs are under consideration for access to a permanent suspension bridge. Design 1A will cost $2.8 million to build and $200,000 per year to maintain. Design 18 will cost $3.6 million to build and $40,000 per year to maintain. Both designs are assumed to be permanent. Use an AW-based rate of return equation to determine (a) the breakeven ROR and (b) which design is preferred at an MARR of 15% per year. a) The breakeven ROR IS % b) At an MARR of 15% per year, design 18 is preferred