Which of the following correctly explains how chemical molecules in the air trigger a nerve impulse to the brain for the sense of smell.

Select one:

a.
The chemicals are broken down by fluids in the nose, and those component parts are absorbed by the cell to trigger a nerve

impulse.

b.
The chemicals “blow by” the cilia of the dendrites as they are breathed in, causing them to bend and trigger a nerve impulse.

c.
The chemicals dissolve in fluid surrounding cilia extending from the dendrites of olfactory receptors and bind to the cells

triggering a nerve impulse.

d.
The chemicals are absorbed by olfactory receptors in the lining of the nose and move into the cell to trigger a nerve

impulse.