Beamer itemize: when changing an item to a figure item alert doesn't work

Question

I did a presentation, where I have an "animated" list, with the current item showing in red. After showing the last item I want to change the last item to a figure, to have a more picturesque way of talking about that last item. My problem is that with the last item I couldn't get the alert to work.

\documentclass{beamer}
\usepackage{todonotes}
\begin{document}
    \begin{frame}
        \frametitle{Minimal working example}
        \begin{itemize}
            \item[]<2-|alert@2> A,

            \item[]<3-|alert@3> b,

            \item[]\only<4|alert@4>{ and c.} \only<5>{ \missingfigure[figheight=0.4\textheight]{Picture of c.}}
        \end{itemize}
    \end{frame}
\end{document}

This generates a five page pdf and what I would want is that on the fourth page, when the "and c." shows up, the "and c." should be red, but it is not. What am I doing wrong?

Thanks in advance!

Answer 1

Is this what you want?

        \item<4-|alert@4>[]%
        \only<4>{and c.}%
        \only<5>{\missingfigure[figheight=0.4\textheight]{Picture of c.}}