A: Yes
B: Yes
C: No
Explanation:
For a line to be perpendicular, the slope must be a negative reciprocal. The slope in each of these equations is the number with x as it's coefficient. The negative reciprocal of 3x is -1/3x. The y intercept is the other number in the equation, the y intercept can be any number as long as the slope is perpendicular, so all but A are perpendicular. B is also yes because B is perpendicular, with the same slope.
