The measurement of the electron position is associated with an uncertainty in momentum, which is equal to $1\times 10^{-18}{\text{g cm s}}^{-1}$. The uncertainty in electron velocity is (mass of an electron is $9\times 10^{-28}\text{g}$):

1. A
   $1\times 10^{11}{\text{cm s}}^{-1}$
2. B
   $1\times 10^9{\text{cm s}}^{-1}$
3. C
   $1\times 10^6{\text{cm s}}^{-1}$
4. D
   $1\times 10^5{\text{cm s}}^{-1}$