下面哪段语句不会报错？
选项：

A:x = ones(1,4);nh = 0:2;h = (nh+1)* ones(1,3);n=0:5;y=conv(x,h);stem(n,y);
B:x = [1 2 3];h = ones(1,5);n=0:7;y=conv(x,h);stem(n,y);
C:x = ones(1,5);nh = 0:2;h = (nh+1).* ones(1,3);n=0:6;y=conv(x,h);stem(n,y);