Some alternate strucres proposed for benzene are given. Indicate for each of them how many (i) mono and (ii) di-substuted products are possible. Which structures fits in the isomer number observed for benzen?
iii. `HC -= C - CH_(2) - C -= C - CH_(2)`
iv. `HC -= C-C -= C - CH_(2) - CH_(3)`
v. `HC -= C - CH_(2) - CH_(2) - C -= CH`.
