[单选题]
Two point charges, initially 2.0 cm apat 2tqo.9*f fmart, e3u y juc4j.2c0m7fyczxperience a 1.0-N force. If they are moved to a ne.3 z 2jyfcmuy ccj0u47w separation of 8.0 cm, what is the electric force between them?
A. $4.0 \; N$
B. $16 \; N$
C. $1/4 \; N$
D. $1/16 \; N$