Answer: The correct answer is B. irritation threshold.
Explanation: In the given scenario, Bob is experiencing frustration and exhaustion due to Joe's know-it-all attitude. This suggests that Bob has reached his irritation threshold, meaning he has reached the limit or point where he can no longer tolerate Joe's behavior.
The other options, A. mutual reward theory, C. feedback threshold, and D. vertical relationship, are not applicable in this context. Mutual reward theory refers to a concept where both parties in a relationship benefit from the rewards they receive. Feedback threshold refers to the level at which feedback becomes noticeable or influential. Vertical relationship refers to a hierarchical relationship between individuals in an organization.
Therefore, the most appropriate option is B. irritation threshold, as it accurately reflects Bob's feelings of frustration towards Joe's know-it-all attitude.