Find the Distance Between Two Points Given Their Coordinates $R$ And $S$

Multiple Choice

Find the distance between two points given their coordinates.
-Find the distance between points $R$ and $S$ on a number line, with coordinates $- 7$ and $- 8$ , respectively.

A) $\mathrm { d } ( \mathrm { R } , \mathrm { S } ) = 15$
B) $d ( R , S ) = - 1$
C) $\mathrm { d } ( \mathrm { R } , \mathrm { S } ) = - 15$
D) $d ( R , S ) = 1$