Which of the following is NOT a valid shape option in the SYMBOL statement?

The correct answer indicates that "Circle" is not a valid shape option in the SYMBOL statement, which is used primarily in SAS/GRAPH to define marker attributes for plots.

In the context of marker shapes available in SAS/GRAPH, valid options typically include various geometric shapes like stars, diamonds, and triangles, which can be used to visually distinguish between different data points or groups in a graph. Understanding the available shapes is essential for creating effective visualizations. The specific shapes allowed in the SYMBOL statement are documented in SAS/GRAPH documentation, where common symbols such as "Star," "Diamond," and "Triangle" are confirmed to be part of the acceptable set.

Therefore, "Circle" is not among the recognized shapes in the SYMBOL statement options, making it the unused shape in this context. Recognizing valid symbols helps when defining visual elements in your SAS graphs, ensuring clarity and accuracy in presentations.