What is wrong with the following code fragment?

What is wrong with the following code fragment?

A.
The in site: call template tag has a syntax error. The Argument field, which is a required
argument, is missing.

B.
Nothing. This code fragment will work as expected.

C.
The slot name HelloSlot cannot be repeated for any given content management site.

D.
The template name Detail cannot be repeated for any given content management site.