Answer: b. an adjective
Adjectives are a category of the parts of speech. They are words that are used to give more information about a noun or noun phrase.
The suffix "-esque" is sometimes added to nouns in order to make them adjectives. It means "resembling" or "appearing to be." Picturesque therefore means to "look like a picture." Other similar adjectives are Romanesque, arabesque and statuesque.
When I was given the choice between a surgery that could help me tremendously but would be a big adjustment. Personally, sorry if that isn't the answer you're looking for though.