Question: You are checking someone else's XML document for errors. You notice that the prolog does not have a closing tag. What do you do?

1. Remove the prolog to make sure that the XML document will be properly processed across all platforms.
2. Leave it alone, because the prolog does not require a closing tag.
3. Move the prolog to an external file so that the XML document only has elements with closing tags.
4. Add a closing tag, as al XML elements must have a closing tag.

Answer: The correct answer of the above question is Option B:Leave it alone, because the prolog does not require a closing tag.