A、A. Create a primary zone named ad.contoso.com on your Windows-based DNS server. Create a delegation record for the new zone on the UNIX-based DNS server. Configure forwarders on your Windows-based DNS server. B、B. Create a primary zone named ad.contoso.com on the UNIX-based DNS server. Create a secondary zone on your Windows-based DNS server for the ad.contoso.com domain. C、C. Create a primary zone named contoso-ad.com on your Windows-based DNS server. Create a secondary zone on the UNIX-based DNS server for the contoso-ad.com domain. D、D. Create a primary zone named contoso-ad.com on the UNIX-based DNS server. Create a stub zone on the Windows-based DNS server for the contoso-ad.com domain. Configure conditional forwarders on your Windows-based DNS server for the contoso-ad.com and contoso.com domains.