Answer:
The answer to your question is: the second option
Explanation:
If two lines are parallel, then their slopes are the same
Slope of the lower line :
m = (-d - 0) / (0 + c)
m = -d / c
Slope of the upper line:
m = ( 0 - a) / (b - 0)
m = - a/ b
finally
-d/c = -a/b