How do hazard function and failure density relate?

• A. Hazard h(t) equals survival S(t).
• B. Hazard h(t) is the instantaneous failure rate given survival; failure density f(t) is the derivative of F(t); relation f(t) = h(t) S(t).
• C. Hazard h(t) is the derivative of failure density f(t).
• D. Hazard h(t) is the probability of at least one failure by time t.

Answer: (B)