**Core Concept**
The Kaplan Meier method is a non-parametric statistical technique used to estimate the survival function of a population, accounting for censored data points and time-to-event analysis. This method is particularly useful in medical research to evaluate the effectiveness of treatments and estimate the probability of survival or disease-free status over time.

**Why the Correct Answer is Right**
The Kaplan Meier method is widely used in medical research to analyze time-to-event data, such as the time to recurrence of a disease, time to treatment failure, or time to death. This method takes into account censored data points, where the exact event time is not known, and estimates the survival function using a stepwise approach. The Kaplan Meier estimate is calculated by multiplying the probability of surviving from one time point to the next, while accounting for the number of events that occur at each time point.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because the Kaplan Meier method is specifically designed for time-to-event analysis, whereas the Wilcoxon rank-sum test is used for comparing two groups on a continuous outcome variable.
**Option B:** This is incorrect because the Cox proportional hazards model is a regression analysis technique used to model the relationship between a predictor variable and the hazard rate, whereas the Kaplan Meier method estimates the survival function directly.
**Option C:** This is incorrect because the Mantel-Haenszel test is a statistical method used to compare the odds ratio of a binary outcome across different strata, whereas the Kaplan Meier method is used for time-to-event analysis.

**Clinical Pearl / High-Yield Fact**
The Kaplan Meier method is particularly useful when analyzing data from clinical trials where the primary outcome is a time-to-event endpoint, such as overall survival or progression-free survival. Remember to use this method when analyzing data from trials where the event of interest is not necessarily the primary outcome, but rather the time to occurrence of the event.

**Correct Answer: C. Kaplan Meier method is used for time-to-event analysis.**