Answer:
A. Mass(only)
Explanation:
The correct answer is A because if the balloon is filled with air, it's filled with matter. Matter is anything that has space and occupies mass. The air occupies mass in the balloon but that doesn't mean that the balloon is heavier. People confuse themselves with mass and weight saying it means the same thing. Mass, like I said is the amount of matter an object contains whereas weight is how much an object weighs.
As per Bernuolli's Theorem total energy per unit mass is given as

now from above equation




now by above equation


Part B)
Now energy per unit weight



Answer:
#2) The spaceship's forward motion must be slowed down so the earth's gravitational pull on it will be stronger than the ship's forward motion.
B is the correct answer for sure bro