Option C or -8/3x+9 =y and 8y=3x -32 is your answer. Simply solve for the y in each equation, and if your slopes are opposite slopes with opposite signs and opposite reciprocal in which the numerator and the denominator is switched, the lines are perpendicular.
y=-8/3x+9------> first line
y=3/8x-4------> second line
Since -8/3 and 3/8 are opposites and opposite reciprocals, choice C is your answer.
Hope I helped!
C. The slopes are negative reciprocals.
-8/3 and 3/8