Which properties of a gas increase linearly as the temperature is increased?

A. Volume and density
B. Volume and pressure
C. Amount of gas and density
D. Amount of gas and volume
I believe the answer is A or D But I am pretty sure the answer is a

No. Look at the P vs V plot at that same site. It certainly is not linear. Do you know what linear means?

See the V vs T graph.

https://www.google.com/search?q=graph+volume+gas+vs+T&ie=utf-8&oe=utf-8

is the answer B?

after looking at graphs I know believe the answer is D. What do you think?

What does linear mean?

it goes in the same directions. If temperature increase then the other properties have to increase

I think you have defined "directly proportional" which is the opposite of "inversely proportional". Here is the definition of linear from the web.

https://www.google.com/search?q=define%3Alinear&ie=utf-8&oe=utf-8
Notice it talks of a straight line. You had the right answer when you started. I simply posted that V vs T plot to show you it was a straight line. The P vs V plot is a curved line. Go back and look at those graphs. The V vs T is straight, V vs P is curved, and the other choices make no sense anyway.

I am so confused. All the answers make no sense. I know the answer has to be A,B or D because of the volume but which one do I choose? A?

It turns out you were wrong; The true answer is B.

You're right. I didn't read the question thoroughly enough. The secret word in the problem is increase. And when T increases the density decreases because the volume increases. density = mass/volume so when volume goes up density goes down. As for B, I looked up the graphs BUT chose P vs V and not V vs T and P vs T so I wasn't even on the right page. Thank you for sharing.