Which of the following is the fourth state of matter?

Which of the following is the fourth state of matter?

A. Gas

B. Liquid

C. Solid

D. Plasma

Explanation:

Indian Scientists have recently developed a theory that helps understand the complicated nature of Sun-Earth interaction’s happening in the magnetosphere, an area of space around Earth that is controlled by the Earth’s magnetic field. This new theory has opened up a plethora of opportunities to unlock the mysteries of the ion-hole structures (a localized plasma region where the ion density is lower than the surrounding plasma).