Four pairs of terms are given as: (i)\[{{a}^{2}}\,\,\text{and}\,\,3ab\] (ii) \[3yz\] and \[6zy\] (iii) \[{{b}^{2}}\,\,\text{and}\,\,-11{{b}^{2}}~\] (iv) \[{{a}^{2}}b\,\,\text{and}\,\,3a{{b}^{2}}~\] Which two given pairs are pairs of unlike terms?

• A.  (ii) and (iii)       
• B.  (ii) and (iv)     
• C.  (i) and (iii)          
• D.  (i) and (iv)