Answer:
D. "If the graph of two variables is not a linear function, then the two variables are not directly proportional"
Step-by-step explanation:
The contrapositive of a statement is basically you changing the conditional part of the statement with its result and then finding the negative of both. This is called Contraposition.
So, for the statement given:
"If two variables are directly proportional, then their graph is a linear function."
The contrapositive will be:
"If the graph of two variables is not a linear function, then the two variables are not directly proportional"
