Identify the structure of the final product (D) in the following sequence of the reactions :

Total number of $\mathrm{sp}^2$ hybridised carbon atoms in product D is ____________.

A compound ' $\mathrm{X}^{\prime}$ absorbs 2 moles of hydrogen and ' X ' upon oxidation with $\mathrm{KMnO}_4 \mid \mathrm{H}^{+}$ gives

The total number of $\sigma$ bonds present in the compound ' $X^{\prime}$ ' is __________.

Two moles of benzaldehyde and one mole of acetone under alkaline conditions using aqueous $$\mathrm{NaOH}$$ after heating gives $$x$$ as the major product. The number of $$\pi$$ bonds in the product $$x$$ is ______.