A metal rod of length 40cm at 20°C is heated to a temperature of 45°C. If the new length of the rod is 40.05cm. Calculate its linear expansitivity

• A.1.2 x \(10^{-5}K{-1}\)
• B.2.5x \(10^{-5}K{-1}\)
• C.3.5x \(10^{-5}K{-1}\)
• D.4.5x \(10^{-5}K{-1}\)
• E.5x \(10^{-5}K{-1}\)