Coulomb's law vs gravitational force

2022 Phase 2 1 question

1. The ratio of Coulomb's electrostatic force to the gravitational force between an electron and a proton separated by some distance is $2.4\times10^{39}$. The ratio of the proportionality constant, $K=\frac{1}{4\pi\varepsilon_0}$ to the Gravitational constant G is nearly (Given that the charge of the proton and electron each $=1.6\times10^{-19}$ C, the mass of the electron $=9.11\times10^{-31}$ kg, the mass of the proton $=1.67\times10^{-27}$ kg):