The correct answer is: A. decreases.
A bubble tube is a device that uses the principle of buoyancy to detect changes in air pressure. When the air pressure changes, the bubbles in the tube rise or fall. The sensitivity of a bubble tube is determined by the size of the bubbles and the distance between them. As the temperature rises, the bubbles in the tube become smaller and closer together. This makes the bubble tube less sensitive to changes in air pressure.
Option B is incorrect because the sensitivity of a bubble tube decreases as the temperature rises.
Option C is incorrect because the sensitivity of a bubble tube is affected by changes in temperature.
Option D is incorrect because the sensitivity of a bubble tube does decrease as the temperature rises.