Which of the following is a positive inotrope?

Correct Answer: C

Rationale: Calcium (Ca²⁺, C) is a positive inotrope, enhancing contractility by increasing sarcomere interaction.

Correct Answer: D

Rationale: Sinus arrhythmia (D) is a normal variation where heart rate increases on inspiration (due to vagal inhibition) and decreases on expiration (vagal tone), common in dogs.

Correct Answer: D

Rationale: The spleen, while important for immune function and blood filtering, is not essential for life; people can survive without it (e.g., after splenectomy). The liver, pancreas, and heart are vital for metabolism, digestion, and circulation.

Correct Answer: B

Rationale: Checking for pitting (indentation after pressure) directly assesses edema severity in an extremity, indicating fluid retention extent. Weighing tracks overall fluid, measuring sizes is less specific, and I/O is indirect.

Correct Answer: C

Rationale: Successful smoking cessation is strongly tied to planning for relapses (e.g., identifying triggers and coping strategies), as it addresses the chronic nature of addiction. Support groups (A) help but are less critical, and B and D ignore the need for comprehensive approaches.