Fig shows the extension $∆$l of a wire of length one

metre suspended from the top of a roof at one end and with a load W connected to the other end. If the cross-sectional area of the wire is 10^-6m², the Young s modulus of the material of the wire will be

• A

  $2\times {10}^{-11}\mathrm{N}/{\mathrm{m}}^2$

• B

  $2\times {10}^{11}\mathrm{N}/{\mathrm{m}}^2$

• C

  $3\times {10}^{-11}\mathrm{N}/{\mathrm{m}}^2$

• D

  $3\times {10}^{11}\mathrm{N}/{\mathrm{m}}^2$