If an \operatorname{arc} of 45^{\circ} on circle A has the same length as an arc of 30^{\circ} on circle B, then the ratio of the area of circle A to the area of circle B is
Answer Choices
A. \dfrac{4}{9}
B. \dfrac{2}{3}
C. \dfrac{5}{6}
D. \dfrac{3}{2}
E. \dfrac{9}{4}