Acquaintanceships with Casual Friends at Work or School Could Be

Acquaintanceships with casual friends at work or school could be characterized by breadth of disclosure but very little depth; however, close friendships involve a higher degree of both breadth and depth. Which statement best explains why this is?

A) Self-disclosure is usually reciprocal.
B) Self-disclosure is influenced by cultural and gender roles.
C) Self-disclosure is intentional.
D) Self-disclosure varies among relationships.