Answer:
The best answer from the choices provided is
Option D : 19
Explanation:
Given:
RS is a Straight Line,
Point D is between points R and S on RS(line on top)
Such that
RD = 7
DS = 12
To Find:
Length of RS = ?
Solution:
RS is a Straight Line ................Given
Point D is between points R and S on RS(line on top)
Such that
R - D - S
Therefore By Line Addition Property we will have

Substituting the given values we get

The best answer from the choices provided is
Option D : 19