The correct answer is: A. Ha and Hb are enantiotopic.
Enantiotopic hydrogen atoms are hydrogen atoms that are in identical environments, but are not superimposable on each other. This means that if you were to rotate the molecule around any axis, the two hydrogen atoms would not be in the same position.
Diastereotopic hydrogen atoms are hydrogen atoms that are in different environments. This means that if you were to rotate the molecule around any axis, the two hydrogen atoms would be in different positions.
In the molecule shown, the hydrogen atoms Ha and Hb are in identical environments. They are both attached to a carbon atom that is bonded to four different groups. However, they are not superimposable on each other. This is because the two carbon atoms that they are attached to are different. Therefore, Ha and Hb are enantiotopic.
The hydrogen atoms Ha and Hc are in different environments. Ha is attached to a carbon atom that is bonded to four different groups, while Hc is attached to a carbon atom that is bonded to three different groups and a hydrogen atom. Therefore, Ha and Hc are diastereotopic.