An XML document that is valid:

A.
complies with XML syntax rules but not the constraints described in a DTD or Schema.

B.
does not necessarily comply with XML syntax rules or the constraints described in a DTD or
Schema, but can be parsed with an HTML browser.

C.
does not necessarily comply with XML syntax rules but only the constraints described in a DTD
or Schema.

D.
complies with XML syntax rules and the constraints described in a DTD or Schema.