If the coordinates of $A$ and $B$ are $(1, 2, 3)$ and $(7, 8, 7)$,then the projections of the line segment $AB$ on the coordinate axes are:

Let the direction cosines of two lines satisfy the equations: $4l+m-n=0$ and $2mn+10nl+3lm=0$. Then the cosine of the acute angle between these lines is:

The direction cosines of the line,which is perpendicular to the lines with direction ratios $-1, 2, 2$ and $0, 2, 1$,are respectively

If a line makes angles $\alpha, \beta, \gamma$ with the positive directions of $X, Y$ and $Z$-axes respectively,then the value of $\sin ^2 \alpha+\sin ^2 \beta+\sin ^2 \gamma=$

The length of the projection of the line segment joining the points $(3, 4, 5)$ and $(4, 6, 3)$ on the line joining the points $(-1, 2, 4)$ and $(1, 0, 5)$ is

$\text{Assertion (A)}$: The direction ratios of line $L_1$ are $2, 5, 7$ and those of line $L_2$ are $\frac{4}{\sqrt{19}}, \frac{10}{\sqrt{19}}, \frac{14}{\sqrt{19}}$. The lines $L_1, L_2$ are parallel.
$\text{Reason (R)}$: The direction ratios of a line $L_1$ are $a_1, b_1, c_1$ and those of another line $L_2$ are $a_2, b_2, c_2$. The lines $L_1$ and $L_2$ are parallel if $a_1 a_2+b_1 b_2+c_1 c_2=0$.
The correct option among the following is