After investigating many properties of gases, Darren hypothesized that the volume of a gas is related to its temperature. Which of the following observations led to his hypothesis?

A.

All of the gases that were investigated were both odorless and colorless.

B.

A balloon filled with air expanded when it was heated and shrank when it was cooled.

C.

A syringe filled with air could be compressed when he applied pressure to the plunger.

D.

all of these