Line J: y=2/3x + 1/2
Line k: y= 1/2x + 2/3
Line L : y= 2/3x + 3/2
Line m: y= 3/2x+ 1/2
These four lines have been graphed on the same coordinate grid. Which lines are parallel to each other?

A: j and m
B: k and L
C: k and m
D: j and L