Use the graph to complete the statement below. Assume that pressure and number of moles of gas are constant in this problem. This graph shows that temperature and volume have _
(A graph of volume versus temperature has temperature in kelvins from 200 to 400 on the horizontal axis, and volume in liters from 0.5 to 1.5 on the vertical axis. 5 points are marked approximately as follows: 225, 0.75; 250, 0.8; 290, 1; 325, 1.1; and 380, 1.3.)

options are:
a direct linear relationship
an inverse linear relationship
a direct non linear relationship
an inverse non linear relationship