What was the first fully animated series produced by Hanna-Barbera?

The Huckleberry Hound Show holds the distinction of being the first fully animated series produced by Hanna-Barbera. Premiering in 1960, it was groundbreaking not only for its animation but also for its format as a half-hour program that featured a variety of cartoons, making it a precursor to many future animated series. The show's success was significant; it won an Emmy Award and demonstrated the viability of animated series on television, leading to a successful era for Hanna-Barbera and paving the way for iconic shows that followed.

While the other options represent important contributions to animated television, they were not the first. The Jetsons, known for its futuristic setting, and Jonny Quest, which focused on adventure, both came after The Huckleberry Hound Show and showcased the evolution of Hanna-Barbera's style and storytelling. Yogi Bear, featuring the beloved character who became a staple of the studio, also emerged later as a spinoff from The Huckleberry Hound Show, further solidifying its legacy as a creative launchpad for the studio.