The direction cosines of the line passing through $P(2,3,-1)$ and the orgin are :

Question

$$\begin {array} {1 1} (a)\;\frac{2}{\sqrt {14}},\frac{3}{\sqrt {14}},\frac{1}{\sqrt {14}} & \quad (b)\;\frac{2}{\sqrt {14}},\frac{-3}{\sqrt {14}},\frac{1}{\sqrt {14}} \\ (c)\;\frac{-2}{\sqrt {14}},\frac{-3}{\sqrt {14}},\frac{1}{\sqrt {14}} & \quad (d)\;\frac{2}{\sqrt {14}},\frac{-3}{\sqrt {14}},\frac{-1}{\sqrt {14}} \end {array}$$