a positron emission tomography (PET) scan is an imaging test that allows your doctor to check for diseases in your body. The scan uses a special dye containing radioactive tracers. These tracers are either swallowed, inhaled, or injected into a vein in your arm depending on what part of the body is being examined
B. Spinal nerves I think, it makes most sense to me.
Answer:
Random assignment.
Explanation:
Random assignment (also known as random allocation, or randomization), in psychology experiments, is randomly selecting participants or units by the use of chance procedures so that each participant or unit has the same chance (equal likelihood) of being assigned to any particular control or treatment group.