Match the Potentially Problematic Element of Causation to the Scenarios

Match the potentially problematic element of causation to the scenarios given.
-A goes to hospital with severe head pains after banging his head on the floor of a playground. B, a doctor negligently examines him and sends him home. Later, A dies from a blood clot on the brain. Medical evidence showed that there was nothing B could have done to save him.

A) Cause in fact ('but for' test)
B) Cause in law (remoteness)
C) Intervening act breaking the chain of causation