Unlike birds, which are highly sensitive to atmospheric pressure, peop

Correct Option B

Original sentence:

Unlike birds,
- which are highly sensitive to atmospheric pressure,
- people have found that paragliding require the use of a variometer since detecting thermal currents are impossible using normal human motion sensitivity.

Sentence meaning:
In contrast similarity of flying, comparison with birds, which are highly sensitive to atmosphere pressure,and can detect thermal currents during their fly, people on other side are unable to measure thermal currents, who are doing paragliding, by normal human motion sensor, to measuring this thermal currents varimotors device is used.
[the use of a variometer crucial for paragliding]

Based on only meaning, A, C, D and E are eliminated,
because the phrase in sentence refer with usage of "That" as that paragliding require the use of a variometer, which is wrong,
here "paragliding" works as a Noun/Subject,
we need paragliding as a verb and instrument varimotors device as Noun to have intended meaning of the sentence.

Remaining with B and only correct.
(Pronoun It refer to "pressure")

A. that paragliding require the use of a variometer since detecting thermal currents are impossible using normal human motion sensitivity
Wrong: SV error: The use ... are (is) : paraglyding ... require(s)

B. the use of a variometer crucial for paragliding since it is impossible to detect thermal currents using normal human motion sensitivity
Left out: Correct


C. that paragliding requires the use of a variometer since detecting thermal currents are impossible using normal human motion sensitivity
Same as A: Wrong


D. paragliding to require the use of a variometer due to the fact that detecting thermal currents is not possible with the use of normal human motion sensitivity
Wrong: Due to is wrongly used

E. that paragliding requires the use of a variometer since detected thermal currents are impossible to handle using normal human motion sensiti
Changes the meaning: Wrongly talks about handling already detected waves

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