Based on the information provided in the table, the average distance from the Sun for Saturn is 9.5 AU and for Neptune is 30 AU. Since Uranus is located between Saturn and Neptune, a reasonable estimate for the distance from Uranus to the Sun would be approximately:
\[ \text{Average of Saturn and Neptune} = \frac{9.5 + 30}{2} = 19.75 \]
Thus, a reasonable estimate for Uranus would be around 20 AU.
Therefore, the correct response is:
20