单项选择题

A.On each Web server, configure a host header value of www.contoso.com. 
B.On each Web server, configure a custom HTTP header value of www.contoso.com. 
C.On Server1, create two host (A) records for www.contoso.com. 
D.On Server1, create a _roundrobin._tcp.contoso.com service locator (SRV) record for each server that has a port value of 80.