Statements
1. All teachers are experienced.
2. Some teachers are spinsters.
Conclusions:
I. Some experienced are spinsters.
II. Some spinsters are experienced.

​Statements
1. All teachers are experienced.
2. Some teachers are spinsters.

​Conclusions:
I. Some experienced are spinsters. (True, since all teachers are experienced and some teachers are spinsters, those spinsters who are teachers are also experienced. So some experienced people are spinsters).
II. Some spinsters are experienced. (True, if some teachers are spinsters, and all teachers are experienced, then those spinsters are also experienced).

So, both Conclusions I and II follows.

Thus, correct option is (d).