I think the answer would be the third option.
Explanation:
my letter are typed by my secretary
What’s the following sentence? I need that to help you answer.
Answer:
1. with
2. of
3. to
4. with
5. for; with
6. of
7. for
8. out; of
9. in
10. in
11. to
12. in
Explanation:
Each of these prepositions makes sense in the context of these sentences.
I hope this helps!