The correct answer is (c) Hypocapnia
To elaborate: Hypocapnia is a condition when the levels of carbon dioxide go lower than the normal levels. This is due to deep or rapid breathing. This state is also called as hyperventilation. Hypoglycemia is the condition when the blood sugar goes low while hypothermia is the condition when the body temperature has gone down. Glucocorticoids are important to the immune system. When conditions like Hypoglycemia, hypothermia or low glucocorticoids happen, the body is actively trying to raise their quantity so the brain signals are high. However, in case of less carbon dioxide, the brain reduces activity to set the balance. Thus, the signals received are slow and of low frequency.