By definition you know that the parallel lines have the same slope and that the slopes of the perpendicular lines satisfy the equation

So, you can take the equation of the second line to the form

Then you have

Now you know that the slope of the first line is -1/2 and the slope of the second line is 2, that is

Let is see if the lines are perpendicular

Since we arrive at a true statement, then the lines are perpendicular.
Therefore, the correct answer is B. Perpendicular.