The isothermal bulk modulus of a perfect gas at normal pressure is

• A

  $1.013\times {10}^5\mathrm{N}/{\mathrm{m}}^2$

• B

  $1.013\times {10}^6\mathrm{N}/{\mathrm{m}}^2$

• C

  $1.,013\times {10}^{-11}\mathrm{N}/{\mathrm{m}}^2$

• D

  $1.013\times {10}^{11}\mathrm{N}/{\mathrm{m}}^2$