How do I align the table where column going beyond the table

I have table where the column is extending beyond in the table in elsarticle. The MWE is as follows:

\documentclass{elsarticle}
\usepackage{booktabs}
\usepackage{tabularx}
\begin{document}\begin{table}[H]
\setlength{\extrarowheight}{3pt}
  \centering
  \caption{Evaluation Metrics}
    \begin{tabularx}{\textwidth}{>{\hsize=0.40\hsize}X>{\hsize=\hsize}X>{\hsize=\hsize}X>{\hsize=0.70\hsize}X}
    \toprule
    \textbf{Metric} &
    \textbf{Formula} &
    \textbf{Explanation} &
    \textbf{Symbols}  \\
    \midrule
    Response Time($q_{r}$) & $q_{r}(n) = \sum_{x=1}^{n}(p_{x}+a_{x})$ & The total time taken by the IVR system to respond to a query. &  $p\Rightarrow$Navigation Time, $a\Rightarrow $Access Time,$x\Rightarrow$Service,$n\Rightarrow$Total number of Services
    \\
    \bottomrule
    \end{tabularx}%
  \label{tab:servicelist}%
\end{table}%


\end{document} 

The screenshot of the table: