What Is the Difference Between Uncertainty and Risk

What is the difference between uncertainty and risk?

A) Risk deals with people, uncertainty with events.
B) Uncertainty deals with people, risk deals with events.
C) Risk exists when the probability of a given event cannot be estimated, whereas uncertainty exists when the probability of a given event can be estimated.
D) Uncertainty exists when the probability of a given event cannot be estimated, whereas risk exists when the probability of a given event can be estimated.
E) b and d