An equiconvex lens is cut into two halves along (i) XOX¢ and (ii) YOY¢ as shown in the figure. Let f, f ¢, f ¢¢ be the focal lengths of the complete lens, of each half in case (i), and of each half in case (ii), respectively Choose the correct statement from the following [CBSE PMT 2003]

• A.            \[{f}'=2f,\,{f}''=f\]              
• B.            \[{f}'=f,\,{f}''=f\]
• C.            \[{f}'=2f,\,{f}''=2f\]            
• D.            \[{f}'=f,\,{f}''=2f\]