Since $$5\times 4 = 20$$, the ones digit of the given product must be $$0$$. 
The ones digit of $$9\times 8\times 7\times 6\times 5\times 4\times 3\times 3\times 4\times 5\times 6\times 7\times 8\times 9$$ is． 
Options:
A) $$0$$ 
B) $$4$$ 
C) $$6$$ 
D) $$9$$ 