Which DNS SRV must the Expressway-E resolve when routing an outbound call to Microsoft clients on Lync or Skype for Business? 

Answer options:

A. _sips._tls.domain.com
B. _sipfederationtls._tls.domain.com
C. _sip._tcp.domain.com
D. _sipfederationtls._tcp.domain.com
E. _sips._tcp.domain.com

C