An electrostatic force of 9.0 N ??

[tex]\longrightarrow \sf D) 9.0 \times 10^6 N/C [/tex]
Given -
Force,F on any charge q in electric field,E is given by -
[tex]\green{ \underline { \boxed{ \sf{F = qE}}}}[/tex]
[tex]\therefore \sf E = \dfrac{F}{q} [/tex]
Putting Values -
[tex]\begin{gathered}\\\implies\quad \sf \dfrac{9}{1 \times 10^{-6}} \quad(1\mu = 10^{-6}) \\\end{gathered} [/tex]
[tex]\begin{gathered}\\\implies\quad \sf 9 \times 10^{6} N/C \\\end{gathered} [/tex]