[单选题]
Suppose that the speed of an electron traveling 2000 m/s isppilo* ui i(.1 known isk, e7bvsmoms3x;(;to an accuracy of mvs7s(kb ;; es,3mxi o1 part in $10^5$ (i.e., within 0.001%). What is the greatest possible accuracy within which we can determine the position of this electron?
A. $2.9 \; mm$
B. $5.8 \; mm$
C. $8.7 \; mm$
D. $1.2 \; cm$