The hudson river school is the name of a group of

People would be the answer to your question

The Hudson River was a mid-19th century American art movement embodied by a group of landscape painters whose aesthetic vision was influenced by Romanticism.

d

explanation:

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.