Answer & Explanation:
Correct Answer: B) Spontaneous heat transfer from a colder body to a hotter body without external intervention.
Explanation: The Second Law of Thermodynamics explicitly states that total entropy in an isolated system always increases over time. Heat cannot spontaneously flow from a cooler body to a warmer body. Option A is entirely possible with external work (like a refrigerator). Option D describes a violation of the Kelvin-Planck statement, but Option B directly violates the core Clausius statement of the law, representing the most fundamental violation.