The Beaufort Wind Scale

[ankit0411]

The Beaufort Wind Scale assigns numbers from 0 to 12 that correlate to a gradient scale of wind velocity and name classification. Meteorologists refer to the wind velocity number 12 on the scale as a "hurricane", indicating that the wind velocity is above 65 knots. At the opposite end of the scale, a 0 may include a wind velocity of up to 1 knot, and is called "calm" under the established system.

Which of the following was an assumption made by the creators of the Beaufort Wind Scale?

a)Meteorologists learn the Beaufort Wind Scale in order to classify the level of wind from "calm" to "hurricane."
b)Wind velocity may be measured accurately enough to classify it on a scale from 0 to 12.
c) If a scale assigns numbers to wind velocity, there must be a corresponding name also assigned.
d)Because it is difficult to measure wind velocity exactly, the Beaufort Wind Scale refers to "calm" as 0, but the wind may be blowing as much as 1 knot
e)The Beaufort Wind Scale is the most accurate and effective scale for expressing wind velocity.

Can anyone please explain this to me ?

The OA is B

Thanks,
Ankit

[Kasia@EconomistGMAT]

Answer a - we don't know why the meteorologists learn the scale, there might be some other reasons and scales available
Answer c - this answer actually repeats the information from the first sentence, so it can't be an assumption
Answer d - it is incorrect because 0 can include a wind velocity of UP TO 1 knot, which is BELOW 1 knot
Answer e - out of scope, it is not stated
Answer b - it must be true, otherwise the scale would be of no use