The most stable conformation of ethylene glycol is .....

$X$ and $Y$ are:

Most stable conformation of $n$-butane is

How many eclipsed and staggered conformations of ethane are obtained during a $0^{\circ}$ to $360^{\circ}$ rotation about the $C-C$ bond?

Statement $I$: Staggered conformation of ethane is more stable than the eclipsed conformation.
Statement $II$: The torsional strain in staggered conformation is more than in the eclipsed conformation.

The structures shown below represent .......