If two lines \(\dfrac{1-x}{3} = \dfrac{7y - 14}{2p} = \dfrac{z - 3}{2}\) and \(\dfrac{7 - 7x}{3p} = \dfrac{y - 5}{1} = \dfrac{6 - z}{5}\) are at right angles to each other, then the value of p will be:
1
\(\dfrac{67}{12}\)
2
\(\dfrac{48}{23}\)
3
\(\dfrac{78}{21}\)
4
\(\dfrac{70}{11}\)