What does the phrase, "The best laid plans of mice and men often go awry" mean?

a
Men are better planners than mice
b
Men and mice are the same
c
It doesn't matter if you are rich or poor, your plans may not go the way you thought.
d
Men and mice share the world and should be kind to each other.

1 answer

c
It doesn't matter if you are rich or poor, your plans may not go the way you thought.