The technique that the author use in this passage is C.stream of consciousness
The passage from "A Portrait of the Artist as a Young Man" by James Joyce exhibits the use of the stream of consciousness technique. Stream of consciousness is a narrative style that attempts to depict the inner thoughts and feelings of a character as they occur in real-time.
In this passage, the author provides insight into the protagonist's thoughts, emotions, and memories in a flowing and continuous manner, giving the reader a glimpse into the character's inner world. Therefore, the correct answer is: C. stream of consciousness