Which is a member of the sighthound family, Caucasian Shepherd Dog or Galgo Español?
Caucasian Shepherd Dog:  The official standard of this breed is fundamentally based on the dogs taken from Georgia. Galgo Español: The Galgo Español ("Spanish galgo") or Spanish greyhound is an ancient breed of dog, specifically a member of the sighthound family.
Galgo Español