Given A m $\times$ n is a matrix, which of the following conditions must be fulfilled so that the system of equations Ax=b has a solution for every b $\epsilon$ R$^m$
A) Every 2 columns in A are linearly independent.
B) All the columns in A are linearly independent.
C) Every 2 rows in A are linearly independent.
D) All the rows in A are linearly independent.
E) The columns in A span R$^m$.
F) The rows in A span R$^n$.
G) All columns in A are not zeroes.
H) All rows in A are not zeroes.
I am certain that A has to be a linearly independent square matrix according to Cramer's rule, which would mean the determinant of A $\not$= 0, and that m=n.
So I believe statements B, E, H are true. However, that is not the case apparently.
What am I missing here?