\textbf{224.} Considering the structure of lactic acid below, which functional group will the resulting polymer have?
$$\text{CH}_3-\text{CH}-\text{COOH}$$
$$|$$
$$\text{OH} \quad \textbf{Lactic acid}$$
\begin{itemize}
\item[(1)] Collar
\item[(2)] Cellulose
\item[(3)] Polyethylene
\item[(4)] Polyethylene terephthalate
\end{itemize}
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