Which beer style is characterized by a high level of carbonation and a crisp finish?

Lager is characterized by a high level of carbonation and a crisp finish, making it the correct option in this context. The brewing process of lagers involves cold fermentation using bottom-fermenting yeast, which typically results in cleaner and crisper flavors compared to other styles. The high carbonation is often a result of the lager's fermentation at lower temperatures, which allows for effective carbonation retention in the finished beer. This combination of high carbonation and a crisp finish is a hallmark of many lagers, including popular substyles such as Pilsner.

Other styles listed differ in their characteristics. Oatmeal Stouts, for example, are darker, fuller-bodied beers with creaminess and lower carbonation. Barleywines are known for being strong, rich, and malty, often with a very low carbonation level due to their high alcohol content and residual sugars. Belgian Dubbels can also have a complex, richer profile, with moderate carbonation but not the same level of crispness that is typical in lagers. Thus, those beer styles do not align with the high carbonation and crisp finish that defines lagers.