Place the Following Steps in the Correct Order for Transduction

Place the following steps in the correct order for transduction of a chemical odorant into a nerve signal. 1. Odorants reach receptors in the cilia of olfactory neurons.
2) cAMP opens ions channels that allow sodium and calcium ions to enter the cell.
3) The G ^-protein activates an enzyme, adenylate cyclase, to convert ATP into cyclic AMP (cAMP) .
4) The binding of an odorant activates a G ^-protein which then detaches from the receptor.
5) The membrane is depolarized. Depolarization that reaches threshold at the axon hillock triggers an action potential and transduction has been achieved.

A) 1, 4, 2, 3, 5
B) 1, 2, 3, 4, 5
C) 1, 4, 3, 2, 5
D) 1, 3, 4, 2, 5