135 a 7 9 0 0 1 11 15 13] b, where a, b e R. Choose the correct statement : Let A 0 1 = There exist values of a and b for which the columns of A are linearly independent. There exist values of a and b for which Ax = 0 has x = 0 as the only solution. For all values of a and b the rows of A span a 3-dimensional subspace of R. There exist values of a and b for which rank (4) = 2.