Answer :

iGreen
We flip the 2nd fraction and multiply.

5/3 * 4/1 = (5 * 4)/(3 * 1) = 20/3 = 6 2/3

So the correct choice should be 'none of the above' unless you made a mistake in your question.
[tex]\frac{5}{3}:\frac{1}{4}=\frac{5}{3}\cdot\frac{4}{1}=\frac{5\cdot4}{3\cdot1}=\frac{20}{3}=\frac{18+2}{3}=\boxed{6\frac{2}{3}}\\\\from\ comment:\\\\\frac{3}{5}:\frac{1}{4}=\frac{3}{5}\cdot\frac{4}{1}=\frac{3\cdot4}{5\cdot1}=\frac{12}{5}=\frac{10+2}{5}=\boxed{2\frac{2}{5}}\leftarrow answer\ \boxed{\boxed{D}}[/tex]