Some common features in chopins writing is a. iambic pentameter and alliteration b. humor and farce c. irony and sex (kate chopin/comparing the story of an hour/the storm)

Some common features in Chopin's writing is C. irony and sex.
It's not A because Chopin primarily wrote prose, and iambic pentameter is usually found in poetry. It's not B because her writing is usually rather depressing and oppressive towards the female sex. So based on this, I'd go with C as the correct answer. Her writing has some sexual scenes which were considered inappropriate for the period (especially The Storm), and irony is omnipresent in The Story of an Hour. 

Adverb or Adjective. I believe it is an adverb