The pressure of the gas decrease as the volume increases.
Option A.
Step-by-step explanation:
The Boyle's law states that in a situation of constant volume and constant temperature, as the pressure of an ideal gas increase, the volume decreases and vice versa. So the mass and the temperature remaining constant, the pressure and the volume of an ideal gas are inversely proportional.
So P ∝ 1/V.
Thus, inside a sealed tube, the mass of the gas is constant. The temperature of the region is said to be constant under the short span of time of this experiment. So as the syringe is pulled, the volume do increase, so the pressure inside the vial decrease.
This is what is plotted in the graph which gives a rectangular hyperbola.