Answer:
B. improved the sport of gymnastics
D. thought gymnastics could help German youth
E. invented the balance beam, rings, and vault
Explanation:
all the choices relates to this passage of the reading...
He thought that the young people of Germany could be encouraged and built up through gymnastics. In the early nineteenth century, Jahn created the first gymnastics club. It helped make the sport popular throughout Germany and later the world. Jahn developed the balance beam, the horizontal bar, the parallel bars, the rings, and the vault. Much of what we see in twenty-first century gymnastics equipment can be traced back to Jahn.