According to Intimacy Theory, Relationship Development Is a Function of Which

According to intimacy theory, relationship development is a function of which of the following?
(1) The depth of partners' self-disclosure
(2) The partners' level of investment
(3) The breadth of partners' self-disclosure
(4) The partners' level of commitment
(5) The partners' responsiveness

A) 2 and 4
B) 3, 4, and 5
C) 1, 3, and 5
D) 1 and 2