The correct answer is A) “pained furrows between her brows.”
The phrase that best shows that Kathryn is tense and possibly unhappy is "pained furrows between her brows.”
This phrase portraits the image of the face of Kathryn with a tense gesture that reflects anxiety or anger. The expression on the face in difficult or painful moments says so much about the moment the person is living. It is something like when someone frowns, expressing tension or irritation.