ANS:D - piezoelectric

Quartz is a piezoelectric material. Explanation:

1. Diamagnetic: Diamagnetic materials are those that have a weak repulsion when placed in a magnetic field. Quartz does exhibit diamagnetic properties, but this is not its primary characteristic.
2. Ferromagnetic: Ferromagnetic materials are those that can be magnetized and retain their magnetization. Quartz is not ferromagnetic.
3. Ferroelectric: Ferroelectric materials are those that have a spontaneous electric polarization that can be reversed by the application of an electric field. Quartz is not ferroelectric.
4. Piezoelectric: Piezoelectric materials are those that generate an electric charge in response to applied mechanical stress or deformation. Quartz is well-known for its piezoelectric properties, which make it useful in various applications such as sensors, oscillators, filters, and piezoelectric actuators. When subjected to mechanical stress or pressure, quartz crystals can generate an electric voltage across their surfaces, and conversely, when subjected to an electric field, they can deform or vibrate mechanically.