Let's break down the changes to the group of mountain gorillas step by step:
- Starting with 10 members.
- 4 females emigrate: 10 - 4 = 6 members.
- 2 females immigrate: 6 + 2 = 8 members.
- 2 gorillas are born: 8 + 2 = 10 members.
- 1 male dies: 10 - 1 = 9 members.
So, after all these changes, the group has 9 members.
The correct response is 9.