To determine the size of the gorilla group after the changes, we can start with the original number of members and adjust according to the changes:
- Original group size: 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
After all the changes, the group size is 9 members.
The correct response is: 9.