Here are the correct answers for each of the sentences:
those men / the umbrellas
B those men's umbrellas
This use of the possessive form "men's" correctly indicates that the umbrellas belong to those men.my parents / the friends
C my parents' friends
This is the correct possessive form for indicating the friends belonging to my parents.Tom and Alice / the car
B Tom and Alice's car
This indicates that the car belongs to both Tom and Alice.King Charles II / the portrait
A the portrait of King Charles II
This is the most straightforward way to indicate possession in this context.the title / the novel I lent you yesterday
A the title of the novel I lent you yesterday
This phrasing clearly indicates that the title refers to "the novel" mentioned.
So the complete answers are: 8. B, 9. C, 10. B, 11. A, 12. A.