The correct option is B By stating that the character's friends think he/she is depressed
The best way to describe a character in a story is to make the reader sympathize with him/her. The character's personal experiences, instances that have led him to become depressed, and bringing the other characters' viewpoints about his depression affect the way the reader perceives the character.
Directly stating that the character is depressed does not really produce a desirable effect on the reader. Hence option A is incorrect.
Option B: By using the voices of others, like the character's friends, the narrator can best portray that he/she is depressed. Hence option B is correct.
Option C: The character's routine does not link up with his emotions. Depression is a state of extreme sadness, an emotion. His routine will tell the reader what he does every day. It does not tell the reader how he feels. Hence C is incorrect.
Option D: Similarly, 'the character's lack of motivation at work' is in relation to his profession and not depression. Hence D is also incorrect.