Answer:(A)
Here's why:
According to the graph,we know that the equation for line l is y=2x.By given that line m is perpendicular to line l,so the slope for line m is -1/2( the product of the slope of two perpendicualr lines is always -1).We also know that line m goes through the point(0,0),by plugging this point to slope-intercept form(y=kx+b),we could easy get the equation for line m,which is y=-1/2x
如果你要考SAT的话就应该能看懂吧 o(∩_∩)o