What is the order of increasing heat of hydrogenation for the following compounds (lowest first) ?

The major product of the following reaction is:

In the given reaction, the product $\mathrm{P}$ is

In the following reaction sequence

X and Y are

The major product of the following reaction is:

The major product in the following conversion is

What is the major product expected from the following reaction?



Where D is an isotope of hydrogen.