Which Hanna-Barbera characters starred in the educational short film, 'Energy: A National Issue' which was shown in schools in the U.S.?

‘Energy: A National Issue’ is a 27-minute animated educational featurette starring The Flintstones, narrated by Charlton Heston and produced by Hanna-Barbera Productions for the Center for Strategic and International Studies of Georgetown University. The film was made available to schools in 16 mm format and also broadcast in syndication on November 22, 1977.

The film follows Fred and Wilma Flintstone through the history of energy sources. As Fred and Wilma (along with Dino, their pet dinosaur) discover many facts about energy and the economy, viewers realize they must use our energy sources more efficiently to buy time to solve the problem. The film uses animation, art, and graphics to dramatize the role energy has played in our lives and outline future energy requirements.