Answer :
In order to find each ratio, we just need to divide the number of elements of each fruit.
For example, to find a ratio of lemon to orange, we should divide the number of lemons by the number of oranges.
So we have:
[tex]\begin{gathered} \text{orange to lemon:} \\ \text{ratio}=\frac{12}{16}=\frac{12\colon4}{16\colon4}=\frac{3}{4}=3\colon4 \\ \text{correct option: C} \\ \\ \text{orange to grapefruit:} \\ \text{ratio}=\frac{12}{8}=\frac{12\colon4}{8\colon4}=\frac{3}{2}=3\colon2 \\ \text{correct option}\colon\text{ E} \\ \\ \text{lemon to grapefruit:} \\ \text{ratio}=\frac{16}{8}=\frac{16\colon8}{8\colon8}=\frac{2}{1}=2\colon1 \\ \text{correct option: G} \end{gathered}[/tex]So the correct options are C, E and G.