The most stable conformation of the following compound is A.
In A, the two methyl groups are in the equatorial position, which is more stable than the axial position. The hydrogen atoms are also in the equatorial position, which is more stable than the axial position.
In B, one of the methyl groups is in the equatorial position and the other methyl group is in the axial position. This is less stable than A because the methyl groups are in different positions.
In C, both methyl groups are in the axial position. This is the least stable conformation because the methyl groups are in close proximity to each other and experience steric hindrance.
In D, the hydrogen atoms are in the axial position. This is less stable than A because the hydrogen atoms are in close proximity to each other and experience steric hindrance.
Therefore, the most stable conformation of the following compound is A.