Benzene in a Kaleidoscope

Consider the following set of reactions,

We start with cyclobutadiene and make it react with chloroform and alkaline KOH at a low temperature to form A .

After the formation of A we heat the container mildly to form B .

B is transferred to a container filled with aqueous KOH, later PCC is added. The container is now mildly heated. This gives us the compound C .

On cooling the reaction mixture the compound C breaks to form D and E . When D and E are heated with diphenylacetylene (separately), we get the same compound X .

When X is heated in presence of Poly Phosphoric Acid, We get the final compound Z .

How many signals appear in compound Z 's H-NMR?

Inspiration :

Problem 19 in the IChO's preparatory paper.