Your network contains an Active Directory forest named contoso.com.
Users frequently access the website of an external partner company. The URL of the website is http://
partners.adatum.com.
The partner company informs you that it will perform maintenance on its Web server and that the IP addresses
of the Web server will change.
After the change is complete, the users on your internal network report that they fail to access the website.
However, some users who work from home report that they can access the website.
You need to ensure that your DNS servers can resolve partners.adatum.com to the correct IP address
immediately.
What should you do?

A.
Run dnscmd and specify the CacheLockingPercent parameter.

B.
Run Set-DnsServerGlobalQueryBlockList.

C.
Run ipconfig and specify the Renew parameter.

D.
Run Set-DnsServerCache.

Explanation:
The Set-DnsServerCache cmdlet modifies cache settings for a DomainName System (DNS) server.
Run Set-DnsServerCache with the -LockingPercent switch.
/ -LockingPercent<UInt32>
Specifies a percentage of the original Time to Live (TTL) value that caching can consume.
Cache locking is configured as a percent value. For example, if the cache locking value is set to 50, the DNS
server does not overwrite a cached entry for half of the duration of the TTL. By default, the cache locking
percent value is 100. This value means that the DNS server will not overwrite cached entries for the entire
duration of the TTL.
Note. A better way would be clear the DNS cache on the DNS server with either Dnscmd /ClearCache (from
command prompt), or Clear-DnsServerCache (from Windows PowerShell).
https://technet.microsoft.com/en-us/library/jj649852.aspx
Incorrect Answers:
A:
You need to use the /config parameter as well:
You can change this value if you like by using the dnscmd command:
dnscmd /Config /CacheLockingPercent<percent>