Letitia is a salesperson. She routinely sells at a lower volume than her colleagues. However, she offers excellent customer service after the sale, and customers routinely give positive feedback when asked to fill out survey. Her supervisor routinely ranks her as either above average or superior on all items on her performance appraisal, including output. This is an example of _ error influencing an appraisal. a. recency b. halo c. validation d. average e. source monitoring