A steel scale is calibrated for\[\text{27}{{\,}^{\text{o}}}\text{C}\text{.}\] The error in a reading of 50 cm at\[30{{\,}^{\text{o}}}\text{C}\]is \[[{{\alpha }_{steel}}=1.2\,\times \,{{10}^{-5}}/{{\,}^{o}}C]\]

• A. 0.018 mm
• B. 0.18 mm
• C. 0.0018 mm
• D. 0.16 mm