单项选择题
按行优先顺序存储下三角矩阵的非零元素，则计算非零元素aij(1≤j≤i≤n)的地址的公式为
A) LOC(aij=LOC(a11)+ix(i+1)/2+j
B) LOC(aij)=LOC(a11)+ix(i+1)/2+(j-1)
C) LOC(aij)=LOC(a11)+ix(i-1)/2+j
D) LOC(aij)=LOC(a11)+ix(i-1)/2+(j-1)
B) LOC(aij)=LOC(a11)+ix(i+1)/2+(j-1)
C) LOC(aij)=LOC(a11)+ix(i-1)/2+j
D) LOC(aij)=LOC(a11)+ix(i-1)/2+(j-1)