There would be 0 Potential energy, which eliminates A. There would be Spring energy, which eliminates C. So B and D are your 2 choices. Since the child is not moving just before the jump, there would be 0 Kinetic energy. So D.
The major species in solution when solid ammonium bromate is dissolved in water is shown below
You’ll need to be sure to count all the atoms in each side of the chemical equation.
