Which of these helped make the middle colonies successful? O A. Family-owned farms O B. Slave labor done by natives O C. Cool summers with little rain D. Equal rights for women

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.