In a topping combination, which option would add richness and sweetness to the taste?

Adding butter as a topping to a potato enhances both richness and sweetness in flavor. Butter is a fat that not only contributes a creamy texture but also brings a natural sweetness, especially when it melts into a warm potato. This combination creates a well-rounded profile, making the dish more indulgent and satisfying.

The other toppings, while they do provide distinct flavors, do not evoke the same level of richness and sweetness as butter does. Bacon bits, for instance, introduce a savory and salty component; sour cream adds tanginess and creaminess; while chives impart a mild onion flavor. Each of these options adds to the overall taste but does not create that rich and sweet taste that butter does when paired with a potato.