[单选题]
An atomic nucleus has a charge o2jvp/t:sx r(g f +6,sdxkp +z7 uw40e. What is the magnitude of the electric field at a distk7z, xds w+6puance of 1.0 m from the nucleus?
A. $5.6 \times 10^{-8} \; N/C$
B. $5.8 \times 10^{-8} \; N/C$
C. $6.0 \times 10^{-8} \; N/C$
D. $6.2 \times 10^{-8} \; N/C$