In packed towers provided with pall rings liquid redistributors are positioned at heights of every 6 metres or 5 - 10 times the column diameter, whichever is less. Maximum size of the pall rings should not exceed __________ of the column diameter.

A. $$\frac{1}{{10}}\,{\text{to }}{\frac{1}{{15}}^{{\text{th}}}}$$

B. $$\frac{1}{5}\,{\text{to }}{\frac{1}{{10}}^{{\text{th}}}}$$

C. $$\frac{1}{{20}}\,{\text{to }}{\frac{1}{{30}}^{{\text{th}}}}$$

D. $$\frac{1}{2}\,{\text{to }}{\frac{1}{4}^{{\text{th}}}}$$

Answer: Option A