What Is the Magnitude of a the Vertical Electric Field $2.1 \mathrm {~g}$

Multiple Choice

What is the magnitude of a the vertical electric field that will balance the weight of a plastic sphere of mass $2.1 \mathrm {~g}$ that has been charged to -3.0 nC? (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²)

A) 6.9 × 10⁶ N/C
B) 7.8 × 10⁵ N/C
C) 1.5 × 10⁶ N/C
D) 2.1 × 10⁶ N/C