When a participle is used to modify a noun, the participle functions as a what?

How do pip's feelings of guilt in chapter 6 fluctuate? a. he feels both guilty and exhilarated by the opportunity to interact with a convict. b. he doesn't feel any true guilt, but rather fear that he will be caught and self-loathing that he stole. c. he feels guilty, but only until the convict is found. d. he feels guilty for lying to joe, but not for stealing from mrs. joe, because he doesn't love her.