8. — I saw David in the teachers' office this morning.Do you know________he was there? prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace> — He went there to hand in his homework. A.. how B.. whether prefix="o" ns="urn:schemas-microsoft-com:office:office"? ?xml:namespace> C.. when D.. why prefix="o" ns="urn:schemas-microsoft-com:office:office"? ?xml:namespace>