JEE Math Practice Question

If the angle between the lines, $${x \over 2} = {y \over 2} = {z \over 1}$$ and $${{5 - x} \over { - 2}} = {{7y - 14} \over p} = {{z - 3} \over 4}\,\,$$ is $${\cos ^{ - 1}}\left( {{2 \over 3}} \right),$$ then p is equal to :

1. A.$${7 \over 2}$$
2. B.$${2 \over 7}$$
3. C.$$-$$ $${7 \over 4}$$
4. D.$$-$$ $${4 \over 7}$$