[Questoin 1] Volume
"Charles's law is an experimental gas law that describes how gases tend to expand when heated." Expand = volume, so this answer is correct
[Question 2] b) move faster
An increase in heat is an increase in energy, which is an increase in particle movement. This means that b is correct, because the particles will be moving faster
[Question 3] a) Celsius
Charles' Law uses Celsius, so when doing Charles' Law problems you should use Celsius, aka °C
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
