How does the Kaplan Meier method use censored observations in its computations?

a. It ignores the censored observations, and only uses the event times for its estimates,

b. It treats the censored observations as if they are event times.

c. It treats the censored observations as being "at risk" of having the event, up until the time of censoring.

d. The Kaplan- Meier method is not an appropriate analysis tool when they are censored observations in a time-to-event dataset.