What the Magnetic Resonance Imaging Machine Actually Measures Is the Relaxation

Multiple Choice

What the magnetic resonance imaging machine actually measures is the relaxation time. Relaxation time is

A) what occurs when brain waves are relatively slow at 4 to 8 Hz
B) the interval that follows the pulse, which is the time taken by the atoms to return to their normal and random state
C) a term for the method for studying tissues using magnetic fields and radio receivers
D) the amount of time that it takes an individual to become relaxed enough that the atoms in their body polarize