You need to create a column that allows you to createa unique constraint. Which two column definitions should you choose?（）

A . The method must return a type of either IEnumerator or IEnumerable. B . The method must return a type of IComparable. C . The method must explicitly contain a collection. D . The method must be the only iterator in the class.

A . Host（A） B . Text（TXT） C . Pointer（PTR） D . Mail exchange（MX）

A . Active Directory Users and Computers B . ADSI Edit C . Group Policy Management Console D . Ntdsutil

A . Active Directory Users and Computers B . ADSI Edit C . Group Policy Management Console D . Ntdsutil

A . Modify the properties of the PSO. B . Modify the account options of the User1 account. C . Modify the security settings of the User1 account. D . Modify the password policy of the Default Domain Policy Group Policy object （GPO）.

A . Modify the properties of the PSO. B . Modify the account options of the User1 account. C . Modify the security settings of the User1 account. D . Modify the password policy of the Default Domain Policy Group Policy object （GPO）.

A . From Windows Explorer， right-click Computer and then click Map network drive. B . From Windows Explorer， right-click Computer and then click Add a network location. C . From Network and Sharing Center， click Set up a new connection or network and then click Set up anew network. D . From Network and Sharing Center， click Set up a new connection or network and then click Connect to aworkplace.