I agree with you, Exhilarated and Pessimism is the correct answer.
Explanation:
Exhilarated means- Very happy, animated.
Whose mood is always "energetic" so Exhilrated would go well with ot.
"Unlike" So Mr. Johnson is the opposite of Mrs. Burrough, and Pessimism means- a tendency to see the worst aspect of things or believe that the worst will happen; a lack of hope or confidence in the future. Which is the opposite of Exhilarated.