$0, 2, 4, 6,$ and $8$ 
A three-digit number can be written as $\overline{6\square4}$~and this three-digit number is divisble by $4$. How many different digits can we fill in this square? 
Options:
[a] $$1$$ 
[b] $$2$$ 
[c] $$3$$ 
[d] $$4$$ 
[e] $$5$$ 