Tonic receptors:.
A) slowly decrease the frequency of action potentials generated to a constant stimulus.
B) are quick to adapt to a particular stimulus intensity.
C) will always decrease to the point where no action potentials are generated.
D) are attune to changes in a parameter, not the extent of that change.

A) slowly decrease the frequency of action potentials generated to a constant stimulus.

Explanation:

Tonic receptors slowly decrease the frequency of action potentials generated to a constant stimulus. These receptors are also called sensory receptor as they continue to produce action potentials over the duration of the stimulus.  Some of the tonic receptors are permanently active.

to plan an idea out before

i only have part a but here is the first one: - lewis and clark are born

- lewis marries sacajawea and clark is jealous  

- clark drowns lewis and then goes to jail