What absurd practice do the inhabitants of Lagado engage in?

The inhabitants of Lagado engage in the absurd practice of extracting sunbeams from cucumbers. This action highlights the satirical tone of Jonathan Swift's work, as it critiques the misguided pursuits of science and the ridiculousness of certain intellectual endeavors during the Enlightenment period. The concept of trying to extract something as intangible as sunbeams from a common vegetable underscores the folly of over-complicated theories and impractical experiments that disregard the laws of nature and reason. This reflects Swift's broader commentary on the absurdity of some contemporary scientific practices, which he viewed as lacking in practical application or common sense.

The other choices represent pursuits that, while potentially absurd, do not capture the unique blend of ridiculousness and satire that the practice of extracting sunbeams from cucumbers embodies, making B the most fitting answer.