Two Tiny Particles Carrying Like Charges of the Same Magnitude $1.0 \mathrm {~mm}$

Multiple Choice

Two tiny particles carrying like charges of the same magnitude are $1.0 \mathrm {~mm}$ apart. If the electric force on one of them is $5.0 \mathrm {~N}$ , what is the magnitude of the charge on each of these particles? $( k =$ $1 / 4 \pi \varepsilon _ { 0 } = 9.0 \times 10 ^ { 9 } \mathrm {~N} \cdot \mathrm { m } ^ { 2 } / \mathrm { C } ^ { 2 }$ )

A) $2.4 \times 10 ^ { - 2 } \mathrm { C }$
B) $4.5 \times 10 ^ { 4 } \mathrm { C }$
C) $2.4 \times 10 ^ { - 8 } \mathrm { C }$
D) $2.4 \times 10 ^ { - 5 } \mathrm { C }$