CAYLEY 2015 Problem 12

Past Contests CAYLEY 2015
, ,
1

The points (-1,q) and (-3,r) are on a line parallel to \displaystyle y=\frac32x+1. What is the value of r-q?

Answer Choices
A. 3
B. \frac43
C. -\frac34
D. -\frac43
E. -3