Answer: A. When is creating a new vaccine appropriate?
D. How did the hole in the ozone layer form?
Explanation:
Science can answer questions or inquiry by utilizing suitable experimental methodology or by direct observation on something which can prove a reason for the cause of a natural phenomena.
Among the options given A. When is creating a new vaccine appropriate? and D. How did the hole in the ozone layer form? are correct. As these involves both experimental and observatory study to be answered.
If the reaction is really exothermic (and it is) then the water would spatter all over the place. It would boil off if the container could hold it. It would also react according to the following reaction.