Answer:
Experimenting.
Step-by-step explanation:
Relational Model was the model developed by Mark L. Knapp. Knapp's model of relationship helps to analyze the relational development, how relations are built, on what basis they last, and how they tend to end.
The model is divided into two phases: Escalation Model and Termination Model, each phase is subdivided into five stages.
According to Knapp's model of escalation, Sam and Chris are at the second stage i.e. experimenting.
Experimenting is the stage at which the couples start to know each other. It is also known as the probing stage as they try to know each other by asking certain questions, for example, 'What you like to do in your leisure time?'
In the given case, Sam and Chris are engaging in the experimenting stage of the relational model as they are trying to know each other and to know what they have in common.
So, the correct answer is experimenting.