A hollow non-conducting cone of base radius $$R = 50\ \text{cm}$$ and semi vertical angle $$15^\circ$$ has been uniformly charged on its curved surface up to three-fourth of its slant length from base with a surface charge density $$\sigma = 2.5\ \mu\text{C}/\text{m}^2$$. The electric field produced at the location of the vertex of the cone is

A

$$\frac{\sigma\ln 2}{2\varepsilon_0}$$

B

$$\frac{\sigma\ln 2}{4\varepsilon_0}$$

C

$$\frac{\sigma\ln 2}{8\varepsilon_0}$$

D

$$\frac{\sigma\ln 2}{16\varepsilon_0}$$