Correct Answer: C

Rationale: A pulsating mass can indicate an abdominal aortic aneurysm (AAA), which is a critical condition.

Correct Answer: A

Rationale: Antihistamines should be avoided in children with sinusitis, as they can dry secretions and worsen symptoms.

Correct Answer: B

Rationale: The lymphatic ducts drain into the venous system, specifically at the junction of the subclavian and internal jugular veins.

Correct Answer: A

Rationale: Epinephrine is the first-line treatment for anaphylaxis, as it rapidly reverses the effects of severe allergic reactions.

Correct Answer: A

Rationale: Heat therapy can help relieve pain and stiffness in osteoarthritis by promoting blood circulation and reducing muscle spasms.