The correct option is C the way the character talks
"A character sketch is a description made for the purpose of guiding the writer on such assignments as introducing a particular character to the reader in such a way that both the writer and readers can have a quick overview of the character's attributes; including but not limited to physical appearance, idiosyncratic (individual) tendencies in different circumstances, state of mind as shaped by former experiences and how these will affect their future actions."
The closest way of portraying a character, from these options, is 'the way the character talks'. This is the trait of a character, and can help the reader form an image of the character in mind.
His favourite song, movie, or dog's name are external factors that do not shape the character.
Hence option C is correct and A, B and D are wrong.