All free charges are integral multiples of a basis unit charge e. Then quantization rule of electric charge implies
A. $Q = e$
B. $Q = \dfrac{1}{e}$
C. $Q = ne$
D. $Q = {n^2}$

Hint: In order to explain this question we should know the concept of charge. Charge is the property associated with matter due to which it produces and experiences electric and magnetic effect. Also it contains protons and electrons.

Complete step by step solution:
According to the properties of charge, electric charge can exist only as an integral multiple charges of an electron. The electric charge is discrete. The charge of an electron is considered as the basis of any charge system i.e.

$q = \pm ne$

Where, q = charge
     n = integer
     e = charge of an electron = $1.6 \times {10^{ - 19}}C$

It is not possible to have a charge less than the charge of an electron to any system.

The possible electric charge values are
$q = \pm e, \pm 2e, \pm 3e, \pm 4e,...........etc$

The charge of ${e^ - }$ to any system $1.6 \times {10^{ - 19}}C$ is the minimum charge of any system.

Thus, option C is the correct answer.

Note: The charge consists of proton and electron. It is the smallest particle ever discovered. Both charges are the same in magnitude but opposite signs. If a body possesses n, protons and $n_2$ electrons, then net charge on will $\left( {{n_1} - {n_2}} \right)e$ i.e. ${n_1}(e) + {n_2}( - e) = \left( {{n_1} - {n_2}} \right)e$