In season 3 of "The Office," Jim says that a black bear is best when he confuses Dwight with a fake version of Dwight’s favorite catchphrase.
The exchange appears in "Product Recall," the 21st episode of season 3. Jim imitates Dwight’s intense, overly serious style by declaring, "Bears. Beets. Battlestar Galactica." He then asks Dwight what kind of bear is best and answers himself: "Black bear." Dwight objects that the question is debatable, giving Jim the opening to repeat the phrase.
The joke works because Dwight is genuinely obsessed with bears, while Jim is using a small set of facts to create an exaggerated imitation of him. The scene became one of the show’s most recognizable comedy moments and is often remembered together with the related "Bears, Beets, Battlestar Galactica" line. A common mix-up is answering simply "bears" or quoting the entire slogan, but the specific answer to Jim’s question is black bear.