Answer:
As an expert in psychology, I would like to clarify that the self-serving bias is when individuals attribute their successes to internal factors (such as their own abilities or efforts) and their failures to external factors (such as bad luck or other people's actions). In the given scenario, the patient is blaming the physician for her failure to lose weight, which is an external factor, and may reflect the self-serving bias.
If the patient has not lost any weight after a month and still believes that she has done everything right, then the most likely reflection of the self-serving bias would be option C, where the patient believes that she actually has lost weight, but that the scale is wrong. This is an example of the self-serving bias because the patient is attributing her perceived weight loss to internal factors (her own efforts), while dismissing external factors (the accuracy of the scale) that may have contributed to the lack of weight loss.