Step 1: Understanding the Concept:
For a planet in a circular orbit, gravity supplies the centripetal force: \(\frac{GMm}{r^2} = \frac{mv^2}{r}\), so \(v = \sqrt{\frac{GM}{r}}\).
Step 2: Ratio:
\[ \frac{v_A}{v_B} = \sqrt{\frac{r_B}{r_A}} = \sqrt{100} = 10 \]
The planet closer to the sun moves faster, which is consistent with the ratio being greater than 1.
Final Answer:
The ratio of the speeds is 10, option (C).
\[ \boxed{10} \]