[单选题]
Three identical charges of 3.0 mC are placed at the vertices ofc5cvj 7+j n1sa an equilateo/ v)sej;v.jz ral triangle which measures 30 cm on a side. What is the magnitude of the electrostatic force which acts on an es;vvo.j j/)zy one of the charges?
A. $1.6 \; N$
B. $1.8 \; N$
C. $2.0 \; N$
D. $2.2 \; N$