A. GLBP and VRRP allow for MD5 authentication， whereas HSRP does not.
B. HSRP allows for multiple upstream active links being simultaneously used， whereas GLBP  does not.
C. GLBP allows for router load balancing of traffic from a network segment without the different  host IP configurations required to achieve the same results with HSRP.
D. Unlike HSRP and VRRP， GLBP allows automatic selection and simultaneous use of multiple  available gateways.
E. GLBP allows for router load balancing of traffic from a network segment by utilizing the creation  of multiple standby groups.