The correct answer is D. 3v.
A pressure sensor is a device that measures pressure. It can be used to measure the pressure of air, water, or other fluids. Pressure sensors are used in a variety of applications, including automotive, industrial, and medical.
The operating voltage of a pressure sensor is the voltage that is required to power the sensor. The operating voltage of a pressure sensor can vary depending on the type of sensor and the manufacturer. However, most pressure sensors operate on a voltage of 3 volts.
Option A, 3.5 volts, is not a common operating voltage for pressure sensors. Option B, 1.5 volts, is a common operating voltage for some types of pressure sensors, but it is not the most common operating voltage. Option C, 5 volts, is a common operating voltage for some types of electronic devices, but it is not the most common operating voltage for pressure sensors.
Therefore, the correct answer is D. 3v.