設$$N$$爲$$5$$的倍數．一個紅球與$$N$$個綠球隨意地排在一直線上．令P(N) 表示至少有$$ \frac{3}{5} $$的綠球排在紅球同一側的概率．顯然$$P（5） =1$$，且當$$N$$非常大时P(N) 趨近於$$ \frac{4}{5} $$．試問使得$$ P(N)\textless{} \frac{321}{400} $$最小的$$N$$，其各位數的數字和爲多少？  Let N be a positive multiple of 5. One red ball and N green balls are arranged in a line in randon order. Let  P(N)be the probability that at least$$ \frac{3}{5} $$ of the green balls are on the same side of the red ball. Observe that  $$P(5)=1$$ and that P(N) approaches$$ \frac{4}{5} $$ as N grows large. What is the sum of the digits of the least value of  $$P(N)\textless{} \frac{321}{400} $$
选项为:A:$$12$$  B:$$14$$  C:$$16$$  D:$$18$$  E:$$20$$  请回答其中一个选项.