Anyone know this geometry question? 10 min left! will give brainiest

Angle 3 and angle 6 are corresponding angles, which means they are equal. In order for the lines to remain parallel, angle 3 and angle 6 would need to remain equal. If something is done to angle 6, then it would have to be done to angle 3 as well in order to keep the angles equal. So, if angle 6 is doubled, angle 3 would also have to be doubled. 

The answer is B. m< 3 would need to double.

Hope this helps =)