From February 1972 to February 1975, 10 severe viral hepatitis patients from various hospitals in California were placed on steroids therapy. The survival times were 1,4,6,8,11+,12+,12+,13+,13+,14+, where the symbol "+ " represents a censored observation.

Assume that survival times are exponentially distributed S(t)=e^(t) .

A) Compute ni=1i

B) Compute ni=1ti

C) Estimate by maximum likelihood