Final answer:
The transformation that was applied to circle q to create circle q can be described by the rule (x, y) → (-x, -y), which represents a reflection across both the x-axis and the y-axis.
Step-by-step explanation:
The rule that best describes the transformation applied to circle q to create circle q is option 3: (x, y) → (-x, -y).
This rule represents a reflection across both the x-axis and the y-axis. In this transformation, every point on the original circle is reflected to a new location on the new circle.
For example, if point (2, 3) is on the original circle q, it will be reflected to point (-2, -3) on the new circle q'.