A scatter diagram where all data points fall along a straight line sloping downwards from top-left to bottom-right indicates:

A line sloping downwards from the top-left to the bottom-right means that Y decreases as X increases, so the correlation is negative. Since all the points lie exactly on a single straight line, with no scatter around it, the linear relationship is perfect. A perfect negative linear relationship gives r = -1. If the points showed only a downward tendency with some scatter around the line, we would have -1 < r < 0, which is option (D). A perfect upward-sloping line gives r = +1, and a random cloud of points gives r close to 0. Hence the correct option is (E).