The probability that a 50-years-old man will be alive at 60 is `0.83` and the probability that a 45-years-old women will be alive at 55 is `0.87.` Then
A. the probability that both will be alive is `0.7221`
B. at least one of them will alive is `0.9779`
C. at least one of them will alive is `0.8230`
D. the probability that both will be alive is `0.6320`