Suppose the charge of a proton and an electron differ slightly. One of them is -e, the other is $$(e + \triangle e)$$. If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then $$\triangle e$$ is of the order of [Given mass of hydrogen $$m_h = 1.67 \times 10^{-27}$$ kg]

A

$$10^{-37} C$$

B

$$10^{-47} C$$

C

$$10^{-20} C$$

D

$$10^{-23} C$$