Your company has two servers that run Windows Server 2008 R2 named Server2 and Server3. Both servers have the DNS Server server role installed. Server3 is configured to forward all DNS requests to Server2. You update a DNS record on Server2. You need to ensure that Server3 is able to immediately resolve the updated DNS record. What should you do？（）
- 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.