Final answer:
The statement 'It cannot be proportional because a straight line through the points does not go through the origin' is the correct characterization of the graph when it depicts a straight line that does not intersect the origin (0, 0), meaning the relationship is not directly proportional.
Step-by-step explanation:
The relationship between two variables on a graph is indicated by the pattern and alignment of the points plotted. In mathematics, when the graph of two variables forms a straight line and passes through the origin (0, 0), we describe this relationship as directly proportional. Direct proportionality indicates that as one variable increases, the other variable increases at a constant rate, which can be described by the equation y = kx, where k is the proportionality constant.
However, if the graph is a straight line that does not pass through the origin, then the relationship is not directly proportional, but it can still be linear. The general form for these types of linear relationships is given by y = mx + b, where m is the slope and b is the y-intercept. Hence, the correct statement about the relationship, assuming the points lie in a straight line but do not pass through the origin, would be 'It cannot be proportional because a straight line through the points does not go through the origin', making the correct answer to the student's question D.