YournetworkcontainsanActiveDirectoryforest.Theforestcontainsasingledomainnamedcontoso.com.Thedomaincontainsfourdomaincontrollers.Thedomaincontrollersareconfiguredasshowninthefollowingtable.YouplantodeployanewdomaincontrollernamedDC5inthecontoso.comdomain.YouneedtoidentifywhichdomaincontrollermustbeonlinetoensurethatDC5canbepromotedsuccessfullytoadomaincontroller.Whichdomaincontrollershouldyouidentify？（）

<img src='https://img2.soutiyun.com/ask/uploadfile/2019-03-27/fc8a136a49949541a73fa9c86692bc3c.jpg' /> A.DC1 B.DC2 C.DC3 D.DC4