The correct statement about a straight line graph showing total distance traveled versus time of travel for a moving object is:
a: The speed of the object is increasing at a constant rate.
In a distance vs. time graph, a straight line indicates that the object is moving at a constant speed if the line is sloping upwards. If the line is curving, that would suggest variable speed, but a straight line implies a consistent speed. If it's a straight line that slopes upwards, it suggests that the speed is constant, not increasing at a constant rate, but option a may be misleading. Therefore, based on the nature of straight line graphs:
The correct answer might lean more towards confirming that the speed is constant if the line is straight and sloping at an angle. If it's entirely straight and horizontal, that would indicate no movement (option d). Without a specific visual of the graph, it's important to interpret these options relative to the information provided. However, based on the assumptions made from a general distance vs. time graph, none of the given options accurately describe a simple straight-line scenario without additional context.
If there’s no curvature or deviation observed, I suggest revisiting the actual graph as ambiguous descriptions may lead to inaccurate interpretations.