How does the Kaplan-Meier approach to estimating the survival function utilize

information from censored observations?

a. It does not. All censored observations are dropped from the data sample before the curve

is estimated.

b. The Kaplan-Meier approach uses the censored observations when considering who is "at

risk" of an event at a given time in the follow-up period. All censored observations are

considered "at risk" of an event until the time of censoring.

c. The Kaplan-Meier approach treats the censoring times as event times. (i.e. it ignores the

fact that these observations are censored)

d. The Kaplan-Meier approach treats the event times as censoring times.