\(\dfrac{\frac{5}{3}-\frac{1}{6}}{\frac{(0.3)^2}{0.2}}\)

The numerator of the double-decker fraction can be reduced to

\(\frac{5}{3}-\frac{1}{6} = \frac{27}{18} = \frac{3}{2}\)

Next multiply this with the reciprocal of the denominator

\(\frac{3}{2} \times \frac{0.2}{0.09} = \frac{3}{10} \times \frac{1}{0.09} = \frac{3}{0.9} = \frac{1}{0.3} = \frac{1}{\frac{3}{10}} = \frac{10}{3}\)

The answer is Choice C.