Why does air in a room rise when it gains thermal energy from a heater? (1 point)
Responses
a. Its molecules move around more slowly, so there is more space between them, making it less dense than the air above it.
b. Warm air always rises.
c. Its molecules move around more quickly, so there is more space between them, making it less dense than the air above it.
d. Its molecules move around more quickly, so there is more space between them, reducing its mass.
which is the correct answer