Total electric flux coming out of a unit positive charge put in air is
C
$$\left(4\varepsilon_0\right)^{-1}$$
Correct option is B. $$\varepsilon_0^{-1}$$
Total electric flux coming out of a unit positive charge put in air is $$ \dfrac{q}{\varepsilon_0}$$
Since, charge is unit i.e. $$q = 1$$
$$\phi = \dfrac{1}{\varepsilon_0}$$