Based on the graph shown to the right, whose phone cost varies directly with the amount of time spent talking?

Not the answer but here is the graph. 

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.

He could be both if he is shy or confused