Answer:
b. 9:3
Explanation:
To determine the equivalent ratios. reduce each to its lowest form:
[tex]\begin{gathered} 2\colon1=2\colon1 \\ 9\colon3=3\colon1 \\ 8\colon4=2\colon1 \\ 10\colon5=2\colon1 \end{gathered}[/tex]Thus, the ratio that is not equivalent is 9:3.