Correct Answer: D

Rationale: All the listed conditions, central cyanosis, respiratory rate >70 breaths per minute, and grunting on assessment, are indicative of the need for oxygen therapy. Central cyanosis suggests severe hypoxemia, a respiratory rate >70 breaths per minute can indicate respiratory distress, and grunting is a sign of increased work of breathing. Administering oxygen in these situations can help improve oxygenation and support the child's respiratory function, making option D the correct choice.

Correct Answer: C

Rationale: The classical clinical manifestations of diabetes mellitus include polyuria (increased urination), polydipsia (excessive thirst), and weight loss. Diabetic ketoacidosis is not a classical manifestation but rather a serious complication that can occur in individuals with uncontrolled diabetes.

Correct Answer: A

Rationale: Beta-adrenergic agonists like albuterol are bronchodilators that primarily work by relaxing and dilating the bronchioles, which helps to alleviate bronchoconstriction, a characteristic feature of asthma. This action leads to improved airflow and easier breathing for individuals experiencing asthma symptoms.

Correct Answer: C

Rationale: Cabbage is an example of a goitrogen. Goitrogens are substances that can interfere with thyroid function by inhibiting the uptake of iodine. Cabbage contains compounds that can have this effect and should be consumed in moderation by individuals with hypothyroidism.

Correct Answer: C

Rationale: Encouraging the child to drink liquids is essential in managing ketones in urine. Increased fluid intake can help prevent dehydration and aid in flushing out ketones, which is crucial in managing diabetic ketoacidosis, a serious complication of uncontrolled diabetes.