Which of the following is a common feature of Sjögren's syndrome?

Correct Answer: D

Rationale: Sjögren's syndrome is characterized by dry eyes, joint pain, and salivary gland enlargement, making 'All of the above' the correct answer.

Correct Answer: B

Rationale: Thrombocytosis is not commonly associated with serum sickness, whereas inflammation markers like ESR and reduced C3 are expected.

Correct Answer: B

Rationale: Normal anion gap metabolic acidosis is caused by bicarbonate loss, such as in diarrhea, where excessive bicarbonate is lost through stool, leading to acidosis.

Correct Answer: D

Rationale: Digitalis is used to manage chronic cardiac conditions but is not a first-line drug in resuscitation.

Correct Answer: C

Rationale: The anion gap reflects unmeasured anions in plasma. It is calculated as Na+ - (Cl- + HCO3-) and helps differentiate types of metabolic acidosis.