JEE Math Practice Question

If the line y = mx + 7$$\sqrt 3 $$ is normal to the hyperbola $${{{x^2}} \over {24}} - {{{y^2}} \over {18}} = 1$$ , then a value of m is :

1. A.$${3 \over {\sqrt 5 }}$$
2. B.$${{\sqrt 15 } \over 2}$$
3. C.$${{\sqrt 5 } \over 2}$$
4. D.$${2 \over {\sqrt 5 }}$$