Which survival probability is listed for burial within 15 minutes?

• A. 50%
• B. 60%
• C. 70%
• D. 90%

Answer: (D)

In survival analysis, S(t) is the probability a subject has not yet experienced the event by time t. Here the event is burial, so S(15) is the chance someone is still unburied after 15 minutes. Early on, most people haven’t yet reached the event, so the survival probability is high, and it tends to decrease as time passes.

Among the given options, 90% is the only value that reflects a high likelihood of still being unburied after only 15 minutes. The other values (50%, 60%, 70%) would imply a much larger portion had already been buried by that short interval, which is unlikely. So the survival probability listed for burial within 15 minutes is 0.90, or 90%.