Answer: The correct answer is Rationalization.
Explanation: Rationalization is a defense mechanism in which individuals justify uncomfortable or unacceptable behaviors rationally and coherently to avoid consciously acknowledging the true explanation or motive behind said behaviors because it may not be tolerable to them.
Colloquially rationalization can be understood as the act of making excuses for oneself or others to avoid explaining real motives.
In this particular case, Kathleen is rationalizing the act of moving to another state (where her boyfriend resides). She states that he has nothing to do with her decision and goes on to explain that her only reason for moving is that she prefers the climate in the new state.
The correct answer then is a rationalization.