Answer:
The answer is B double-blind study
Explanation:
In this type of scientific study neither the experimenter nor the researcher knows the study sample, during the period that the experiment lasts, in order not to influence the results.
Answer: B) Hyperthyroidism
Explanation: Hyperthyroidism is a situation where thyroxine hormone is produced in higher quantity than the body will usually need by the thyroid gland in the neck region. This usually leads to increase in the metabolism of the body, although the elderly individuals often don't experience any symptoms, some of the symptoms in younger individuals are as follows; Weight loss, excess sweating, excessive hunger, fatigue, heat intolerance, restlessness, hyperactivity, abnormal heart rhythm, fast heart rate, warm skin, weakness of muscles, diarrhea, insomnia, palpitation as well as mood swings.
With the series of symptoms been experienced by the 13 year old girl, these manifestations suggest she is suffering from Hyperthyroidism.