设X<sub>1</sub>,X<sub>2</sub>,…,X<sub>n</sub>…为相互独立同分布的随机变量序列,且E(X<sub>1</sub>)=0,D(X<sub>1</sub>)=1,则<img src="https://nimg.ppkao.com/2019-04/wuacheng/2019041216571911818.jpg?sign=be9a2f8578bf47f3fe257ef432b72524&t=62d6ba7d" />=()
A、0
B、0.25
C、0.5
D、1