Final answer:
A model rocket launched from the roof of a building will go upward.
Step-by-step explanation:
The model rocket launched from the roof of a building will go upward (Option A).
When a rocket is launched, it experiences an upward force that counteracts gravity.
This force is produced by the thrust generated by the rocket engines. As the rocket burns its fuel and expels it out of the bottom, the reaction force propels the rocket upward.
For example, when a firework rocket is launched, it flies straight upward before exploding.
This is because the force caused by burning fuel propels the rocket in an essentially vertical trajectory.