Hamlet feels that is where a woman has a best chance at being faithful, and where she will cause the least amount of damage. After all, as he tells Ophelia also, "why wouldst thou be a breeder of sinners?"; in a nunnery, she won't have children and bear wicked men-like his uncle-that do awful things.
C. I chose that rose for its sweet smell.
This sentence actually has two pronouns used as adjectives. The first is "that". It is an adjective because it describes which rose is being chosen. The second pronoun that's being used as an adjective is "its". "Its" tells us what the smell belongs to. Possessive pronouns are often considered possessive adjectives because they describe who or what is being owned. In this case the rose or "its" owns the smell.
Manner because it is how they walked