More physics Q's:?

Question

1. As a high altitude balloon sinks lower and lower into the atmosphere, it undergoes a decrease in: A)volume B)mass C) density D) weight E) None of these
2. A helium filled balloon released in the atmosphere will rise until A)atmospheric pressure on the bottom of the balloon equals atmospheric pressure on the top of the balloon. B)the balloon and surrounding air have = densities. C)the pressure inside the balloon equals atmospheric pressure. D) all of these E) none of these.

Answer 1

1 is A
2 is B

Answer 2

I thinks is
A
and
D