A new storm drainage system must be constructed right away to reduce periodic flooding that occurs in a city that is in a valley. Five mutually exclusive designs have been​ proposed, and their present worth​ (in thousands of​ dollars) of costs and benefits are the following.System 1 2 3 4 5PW of cost $1000 $4000 $4000 $10,000 $14,000PW of benefits $8000 $8000 $14,000 $16,000 $24,000Which sytem has the greatest B-C ratio?