Determine if b is a linear combination of a a2 and a3 5 HH a 0 12 D 3 15 Choose the correct answer below O A Vector b is a linear combination of a a2 and a3 The pivots in the corresponding echelon matrix are in the first entry in the first column the second entry second column and the third entry in the third column B Vector b is a linear combination of a a2 and a3 The pivots in the corresponding echelon matrix are in the first entry in the first column and the second em the second column OC Vector b is not a linear combination of a a2 and a OD Vector b is a linear combination of a a2 and a3 The pivots in the corresponding echelon matrix are in the first entry in the first column the second entry second column and the third entry in the fourth column