Your network contains a single Active Directory domain named contoso.com.The domain contains a DNS server named Server1 that hosts the contoso.com zone.The network is connected to the network of a partner company. The partner companys network contains a DNS server that hosts a zone named nwtraders.com.You need to ensure that computers in contoso.com can resolve the names of computers in nwtraders.com.The solution must not require any changes to the zone configuration of nwtraders.com.What should you configure on Server1？（）

• A、a conditional forwarder
• B、a GlobalNames zone
• C、a secondary zone
• D、a zone delegation