ANSWER

Step-by-step explanation
In the diagram, line CD passes through

The slope of this line is found using the formula,

We substitute the values to get,



So line CD is the line with slope

From the graph we can see clearly that, the only line that is perpendicular to CD is line FG.
Line FG also passes through


We can verify that the product of these two slopes is negative 1.

Therefore the correct answer is C