Answer:
Part A
1. Who told you about our plans?
2. From whom did you borrow that costume?
3. To whom is that package addressed?
4. My Father, who is a great scientist, invented that gadget.
5. People who are kind are rewarded.
Part B
1. Pass the paper to whomever in your group.
2. Whoever wrote this story is creative.
3. You can play with whoever you want.
4. Whoever made this stew is a great chef.
5. I answered whoever called my name.