I am new to latex; hence, this can be trivial question. However, I could not handle it.

I want to make my subsection title bold and italic. I tried some methods, but I could not accomplish it. 

```
\documentclass[preprint,authoryear,12pt]{elsarticle}
\usepackage[utf8]{inputenc}

\begin{document}

\maketitle

\section{Introduction}
\subsection{My Life}
\end{document}

```

The style of subsection part `My Life` is italic and not bold. I want to make it both bold and italic. By the way, I have to use the document class in sample code above. It is necessity provided by article owners of my university.