Fe Solutiononly one proton nmr signal appears at 416 ppm due

only one proton nmr signal appears at 4.16 ppm due to ten protons present in 2 cyclopentadienyl rings are equilent.

only one C¹³ NMR signal appear from the given structure due to all carbons are similar.(nearly 135ppm)

two possible monoderivative structures are available for the given structure. (2and 3 positions)

three possible di-substitued derivative structures are available for the given structure. (1,1 1,2 1,3 )

this is the correct resonanace structure for given nmr data.