In the diagram, the area of the shaded middle ring is 6 times the area of the smallest circle. The area of the unshaded outer ring is 12 times the area of the smallest circle. What fraction of the area of the largest circle is the area of the smallest circle?
Answer Choices
A. \frac{1}{3}
B. \frac{1}{6}
C. \frac{1}{12}
D. \frac{1}{18}
E. \frac{1}{19}