已知e₁、e₂是不共线的向量，下列各选择项中，a、b共线的是

A．a = e₁ + e₂，b = e₁ e₂                               B．a = e₁ 2e₂，b = e₁ + e₂

C．a = 5e₁ e₂，b = 3e₁ + 2e₂                         D．a = 2e₁ + 4e₂，b = e₁ + 3e₂