Identify (A) to (J), showing all reactions.

Explanation

Du in `(A)=((2n_C+2)-n_H)/(2)=((9xx2+2)-10)/(2)=5^@`
DU in `(B)=((9xx2+2)-18)/(2)=1^@`
1 DU in (B) shows that there is a ring in both (A) and (B), and it is a six-membered ring because the product (E) is benzene.
(A) `underset([Ag(NH_3)_2^(o+)])rarr` White ppt. [Indicates terminal `(C-=C)` bond]
5 DU in (A) can be accounted for `implies` 1 DU for ring
+2 DU for `(C-=C) + 2 DU` for two `(C=C)` bonds [Two `(C=C)` bonds should be in the ring].
Possible structures for (A) are:

From the ozonolysis of (I) and (II), it is clear that the products of ozonolysis from (I) are same as given in the problem. So the structure of (A) is (I).