[单选题]
Two point charges, initial+phf9woqp )9:nxje;uk0 r a2lly 2.0 cm apart,q/2us ),e.hs3kqoxq0 hrk4aj experience a 1.0-N force. If they are moved to a new separat4h2h)xukj/3 q.kasor 0 qsqe, ion of 8.0 cm, what is the electric force between them?
A. $4.0 \; N$
B. $16 \; N$
C. $1/4 \; N$
D. $1/16 \; N$