What Is a Key Difference Between Spores and Seeds

What is a key difference between spores and seeds?

A) Spores are single-celled reproductive structures; seeds are multicellular embryos.
B) Spores are multicellular reproductive structures; seeds are unicellular embryos.
C) Spores have stored nutrients; seeds do not.
D) Spores disperse far distances; seeds are larger and disperse shorter distances.
E) Spores are adapted to mild climates; seeds can withstand dry and cold conditions.