the answer is the second one because in order to create a perpendicular line, the slope of the new equation has to be the opposite reciprocal of the previous slope. An opposite is simply switching signs (Ex: 5 become -5), and a reciprocal is simply switching the numerator and denominator. (Ex: 2 becomes 1/2). so the opposite reciprocal would be switching the sign then flipping the numerator and denominator.
the y intercept does not matter with linear equations