$$\text{A}$$ is a positive number, $$\text{B}$$ and $$\text{D}$$ are two negative numbers, $$\text{C}$$ is zero, which is neither positive nor negative. We choose $$\text{C}$$. 
Which of the following is neither a positive nor a negative number? 
(A) $$15$$ 
(B) $$-23$$ 
(C) $$0$$ 
(D) $$-1$$ 