Using square bracket inside square bracket [duplicate]

Question

I have a two-column layout, and I want to put a specific section with images to span the whole page width. So I use:

\twocolumn[
...
]

So far, so good. However, when I want to include anything in this block that also includes a square bracket ], then this fails (variety of errors depending on what goes on inside the brackets). How should I go around this?

Example error:

\twocolumn[
  \includegraphics[width=15cm]{abc.jpg}
]

Answer 1

\twocolumn[
 {\includegraphics[width=15cm]{abc.jpg}}
]

(Grouping {} added).