Your network consists of a single Active Directory domain. All servers run Windows Server 2003 Service Pack 2 （SP2）.You have two DNS servers named Server1 and Server2. Server1 hosts the primary zone for contoso.com.  Server2 hosts the secondary zone for contoso.com. You need to ensure that when records are updated on Server1， the records are replicated to Server2 in the shortest time possible.  What should you do？（）

• A、On Server1，modify the zone transfer settings.
• B、On Server2，modify the zone transfer settings.
• C、On Server2，enable automatic scavenging of stale records.
• D、On Server1，modify the Time to Live （TTL） of the start of authority （SOA） record.