Read the text and determine if the sentence is true (see options at the end):

How to use a graphic flight computer to find ground speed and true heading<br>Align the wind direction under the " true index " mark by rotating the azimuth plate. If the winds are from 330 ° at 20 knots, align 330 under the true index. Align the grid so the center grommet is over one of the heavy lines.

Sentence: ground speed and true heading can only be found with a graphic flight computer
OPT:
 A). Yes
 B). It's impossible to say
 C). No
B).