If a 2 m long copper wire extends by 1 mm when it is experiencing 5 × 109 N/m2 stress, then the Young's Modulus of this wire is ___________.

• A. 1013 N /m2
• B. 1011 N/m2
• C. 2.5 × 1013 N/m2
• D. 2.5 × 1011 N/m2