Sadie is so fearful of being overwhelmed by anxiety that she rarely steps outside her apartment. The thought of going shopping and getting lost in a crowd terrifies her, so she has her groceries delivered. Because of her fear, she earns her living as a freelance writer, working at home. Sadie's behavior is most characteristic of:
A. agiraogibua
B, generalized anxiety disorder
C. somatoform disorder
D. obsessive-compulsive disorder