i attached the diagram. a) the object whose world line is labeled B is moving along the x-axis T or F? I said false because yes while it is moving along the x axis it's also moving along the y-axis. So it's moving in two dimensions not just one. is my answer and reasoning correct? The world line for object E (a completely horizontal world line) cannot possibly be correct right? The reason behind this is because it has a slope of zero and it must have a slope of one or greater. Having a slope of 1 or less than one means that the object is traveling at the speed of light or faster than the speed of light which is not possible.