Please help!!!!!!!!!!

A driver is suspected of driving under the influence and is pulled over by a cop. The cop administers several field sobriety tests including the horizontal gaze test, the walk-and-turn test, and the one-leg stand test. He also administered a breathalyzer test. Which test is most conclusive?

A) walk-and-turn test

B) horizontal gaze test

C) breathalyzer test

D) one-leg stand test