If the Following Defines a One-To-One Function, Find Its Inverse

If the following defines a one-to-one function, find its inverse. If not, write "Not one-to-one."
- $\begin{array}{l}\begin{array} { c | c } \mathrm { x } & \mathrm { f } ( \mathrm { x } ) \\\hline 2 & 22 \\\hline 10 & - 4 \\\hline 11 & - 12 \\\hline 21 & 20\end{array}\\\\\begin{array} { l | l } \mathrm { x } & \mathrm { f } ^ { - 1 } ( \mathrm { x } ) \\\hline & \\\hline & \\\hline & \\\hline &\end{array}\end{array}$

A) $\begin{array} { c | c } \mathrm { x } & \mathrm { f } ( \mathrm { x } ) \\\hline 2 & 20 \\\hline 10 & 22 \\\hline 11 & - 4 \\\hline 21 & - 12\end{array}$
B) $\text { Not one-to-one }$
C) $\begin{array} { c | c } \mathrm { x } & \mathrm { f } ^ { - 1 } ( \mathrm { x } ) \\\hline 22 & 2 \\\hline - 4 & 10 \\\hline - 12 & 21 \\\hline 20 & 11\end{array}$
D) $\begin{array} { c | c } \mathrm { x } & \mathrm { f } ^ { - 1 } ( \mathrm { x } ) \\\hline 22 & 2 \\\hline - 4 & 10 \\\hline - 12 & 11 \\\hline 20 & 21\end{array}$