Two 4.0 kg masses are 1.0 m apart on a frictionless table. each has 1.0 μc of charge. what is the magnitude of the electric force on one of the masses?

Coulomb's law:

  Force = (8.99×10⁹ N m² / C²) · (charge₁) · (charge₂) / distance²

            = (8.99×10⁹ N m² / C²) (1 x 10⁻⁶ C) (1 x 10⁻⁶ C)  / (1.0 m)²

            = (8.99×10⁹ x 1×10⁻¹² / 1.0)  N

            =      8.99×10⁻³  N

            =        0.00899 N repelling.

Notice that there's a lot of information in the question that you don't need.
It's only there to distract you, confuse you, and see whether you know
what to ignore.

-- '4.0 kg masses';  don't need it. 
   Mass has no effect on the electric force between them.

-- 'frictionless table';  don't need it.
   Friction has no effect on the force between them,
only on how they move in response to the force.

To use anything transparent

My answer is opptionc, just check with anyone else