What does it mean to say that virtue $($or goodness$)$ is the "mean" for Aristotle, and why is it important?

a$.$ It means that we should consider the intent of actions, not the consequences.

b$.$ It means we should take an average, or arithmetic mean, of the responses on any issue to guide conduct.

c$.$ It means experiencing emotions at the right times in the right way for the right causes.

d$.$ It means that being persistent or even mean is sometimes necessary in order to get respect from others.