I believe the answer would be graph B. This is because we can see that the value inside the parenthesis is between 0 and 1, which means it is decreasing exponentially (because it has an exponent). We can plug in 0 for x, and see that the y intercept has to be 6, so this leaves us with graphs A, B, and C. Now we can see that graph A makes absolutely no sense, it doesn't show a graph of an exponential function and really isn't even a graph. I mean it does look like it is the bottom of a quadratic, but still. Anyway, this leaves us with graphs B and C. Now as we know the graph is an exponential decrease. This means that as x increases, y should decrease. We can see this happening in graph B. Hope this helps. Feel free to ask more questions, or ask questions about my explanation.