An elastic object strikes to ground and compress when it touches the ground. What is energy transformation?

a- gravitational to electric
b- electric to gravitational
c- A ---Answer
i don't know which one is right for the second one.
A study shows treatment of peptic ulcer with anti bodies result in improvement in many patients.
Which one is right option?
a..Antibodies neutralize stomach acid
b..Antibodies should be prescribed to prevent ulcer
c…Ulcer caused by bacteria infection.