[单选题]
A metal sphere of radius 10 cm carries a charge of +2.0 ou. ho8 jdim*3m3 ,8x wakz/odkC. What is the magnitude of the electric kkx3/,8da ozw field 5.0 cm from the sphere's surface?
A. $4.0 \times 10^{5} \; N/C$
B. $8.0 \times 10^{5} \; N/C$
C. $4.0 \times 10^{7} \; N/C$
D. $8.0 \times 10^{7} \; N/C$