In the Context of a Voting System, Unanimity Means That $X$

In the context of a voting system, unanimity means that:

A) if option $X$ beats option $Y$ , and $Y$ beats $Z$ , then $X$ should beat $Z$
B) if $A$ beats $B$ , and $B$ beats $C$ , then $A$ should beat $C$
C) the ranking between any two outcomes $\mathrm{A}$ and $\mathrm{B}$ should not depend on whether some third outcome $C$ is also available
D) if everyone prefers option $X$ to option $Y$ , then $X$ should beat $Y$