Final answer:
The relational dialectic causing tension is autonomy-connected.
Step-by-step explanation:
The relational dialectic causing tension in the scenario is the autonomy-connected dialectic. Autonomy refers to the need for independence and individuality, while connectedness refers to the need for closeness and interdependence in a relationship. In this scenario, Jeff is exhibiting a desire for connectedness by calling Diane twice a day, while Diane is experiencing a need for autonomy and feeling suffocated by his constant attention.