perp 2-161想不通，请教，谢谢~

161.       16120-!-item-!-187;#058&010949

In the xy-coordinate plane, line m and line k intersect at the point (4, 3).  Is the product of their slopes negative?

(1)  The product of the x-intercepts of lines m and k is positive.

(2)  The product of the y-intercepts of lines m and k is negative.

答案是C.可是我怎么觉得B就可以得出结论阿？

由（2）两条直线的y轴截距之积是负，那么两条直线的斜率必定一正一负，也就是说the product of their slopes is negative.

请大家帮我看看，我哪里想错了呀？谢谢~

y intercept是正的，x intercept可正可负，斜率也可正可负