Your network contains an Active Directory forest. The forest contains two domains named contoso.com and nwtraders.com.You have a DNS server named DNS1. DNS1 hosts Active Directory-integrated zones for contoso.com and nwtraders.com.You discover that client computers in contoso.com cannot use single-label names to access servers in nwtraders.com.You need to ensure that contoso.com computers can access nwtraders.com servers by using single-label names.What should you modify？（）

• A、the DNS suffix search order on DNS1
• B、the DNS suffix search order on the client computers
• C、the root hints servers on DNS1
• D、the security settings of the nwtraders.com zone