单项选择题
A. Run the dnscmd . /clearcache command on Server3.
B. Run the ipconfig /flushdns command on Server3.
C. Decrease the Time-to-Live (TTL) on the Start of Authority (SOA) record of na.contoso.com to 15 minutes.
D. Increase the Retry Interval value on the Start of Authority (SOA) record of na.contoso.com to 15 minutes.
单项选择题 Your company has a single Active Directory forest that has an Active Directory domain named na.contoso.com. A server named Server1 runs the DNS Server server role. You notice stale resource records in the na.contoso.com zone. You have enabled DNS scavenging on Server1. Three weeks later, you notice that the stale resource records remain in na.contoso.com. You need to ensure that the stale resource records are removed from na.contoso.com. What should you do？（）
单项选择题 Contoso Ltd. has a single Active Directory forest that has five domains. Each domain has two DNS servers. Each DNS server hosts Active Directory-integrated zones for all five domains. All domain controllers run Windows Server 2008 R2.Contoso acquires a company named Tailspin Toys. Tailspin Toys has a single Active Directory forest that contains a single domain. You need to configure the DNS system in the Contoso forest to provide name resolution for resources in both forests. What should you do？（）
多项选择题 Your company has a single Active Directory forest that has six domains. All DNS servers in the forest run Windows Server 2008 R2.You need to ensure that all public DNS queries are channeled through a single-caching-only DNS server. Which two actions should you perform？（）