Final answer:
Your feeling of anger is due to an emotional appraisal, where you negatively perceive your boss's criticism against your hard work, leading to the emotion of anger in line with Lazarus's cognitive-mediational theory.
Step-by-step explanation:
Lazarus would say that your feeling of anger occurred because of your emotional appraisal of the situation. According to Lazarus's cognitive-mediational theory, our emotions are determined by our appraisal of the stimulus. This appraisal is immediate and often unconscious, and it mediates between the stimulus and the emotional response. The appraisal involves making attributions, which are mental explanations for why something occurred. In your case, you likely feel that your boss's criticism is unfair given your hard work, and this negative cognitive appraisal leads to the emotion of anger.