The normal WBC count in an adult human being is 

• A

  10,000-15,000 ${\mathrm{mm}}^{-3}$

• B

  60,000-80,000 ${\mathrm{mm}}^{-3}$

• C

  3,000-5,000 ${\mathrm{mm}}^{-3}$

• D

  6,000-8,000 ${\mathrm{mm}}^{-3}$