Which One of the Following Is Not a Valid Enumerated

Multiple Choice

Which one of the following is not a valid enumerated type declaration?

A) enum Iron { Melting = 2795, Boiling = 4982 }
B) enum SpeedLimit { City = 35, Highway = 60 }
C) enum Temperature { Cold = 20, Hot = 90 }
D) enum Voltage { Orange = 3.3, Green = 5.0 }