The author of "The Open Window" describes the fifteen-year-old niece as being "a very self-possessed young lady." In what way can the character of the niece be described? A. Shy B. Confident C. Evil D. Selfish

A self-possessed person is one who is very assured of his or her own capabilities, is quite calm and collected, and just generally cool.

Having this in mind, the way that the character of the niece can be described is B. confident.

The other options don't make much sense here.