Of the following beer styles, which would have the lowest alcohol content?

The beer style with the lowest alcohol content among the options is typically Best Bitter. Best Bitter is designed to be an approachable, sessionable beer that often ranges between 3.2% to 4.5% alcohol by volume (ABV). This style emphasizes a balance of malt and hop flavors while maintaining a drinkable quality, making it perfect for social settings where moderation is considered.

In contrast, the other styles listed tend to have higher alcohol content. American Porters often have an ABV ranging from 4.0% to 6.5%, providing a richer flavor profile due to the use of roasted malts. Oatmeal Stouts also usually hover around a similar range or slightly higher, benefiting from the smoothness that's added by oats. Wee Heavy is a strong Scottish ale that typically has an ABV of 6% to 10%, making it one of the higher alcohol styles listed here.

Thus, Best Bitter stands out as the style with the lowest alcohol content, making it an excellent choice for those seeking a flavorful yet lower-alcohol beer.