Final answer:
To calculate the circumference without a given radius is impossible; if the number 30 represents the diameter, then the radius is 15 units, leading to a circumference of 94.2 units, which does not match any of the provided options.
Step-by-step explanation:
The circle's center is located at (3,1), but the radius is not provided in the question. To find the circumference of a circle, we use the formula C = 2πr where π (Pi) is approximately 3.14 and r is the radius. Without the radius, we cannot determine the exact circumference. However, if we are to assume that the number in parentheses at the end of the original question, (30), refers to the diameter of the circle, then the radius would be half of that, 15 units. Applying the formula, we get C = 2 * 3.14 * 15, which calculates to 94.2 units, none of the provided options (a-d) match this result. Please provide the radius or diameter of the circle for an accurate calculation of the circumference.