Bookmarks in PDF file

[felixweinstein46]

For compiling LaTeX files, I use the command PDFTeXify
(MiKTeX, ver.24.1 in the WinEdt 11.2 environment).
My source files use the hyperref package.
After compilation, in Bookmarks for

\section{Groups $\C_n$ and $\widetilde{\C}_n$}\label{Cn}

I get the bookmark

Groups Cn and C"0365Cn.

How can I make similar links have their natural form,
that is, look like in the PDF file?
What parameters in hyperref or elsewhere need to be changed?