Assume the below life table was constructed from following individuals who were diagnosed with a slow-progressing form of prostate cancer and decided not to receive treatment of any form. Calculate the survival probability at year 1 using the Kaplan-Meir approach and interpret the results.

Time in Years	Number at Risk, Nt	Number of Deaths, Dt	Number Censored, Ct	Survival Probability
0	20			1
1	20	3
2	17		1
3	16	2	1

1. The probability of surviving 1 year after being diagnosed with a slow-progressing form of prostate cancer is .85.
2. The probability of surviving 1 year after being diagnosed with a slow-progressing form of prostate cancer is .85 for the individuals being followed in this study.
3. The probability of surviving 1 year after being diagnosed with a slow-progressing form of prostate cancer is .85 for individuals who decided against all forms of treatment.
4. The probability of surviving 1 year after being diagnosed with a slow-progressing form of prostate cancer is .85 for the individuals being followed in this study and for individuals who decided against all forms of treatment.