number of wild salmon--SC

[AnuragRatna]

In Scotland, the number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting, by pollution, and by various other threats to the fish's habitat.

A number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting
B number of wild salmon is reduced because deep-sea and coastal netting is not controlled
C numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting
D wild salmon's numbers are reduced by deep-sea and coastal netting that is not controlled
E wild salmon's numbers have been reduced by uncontrolled deep-sea and coastal netting

[phanikpk]

IMO E

Because of parallelism by uncontrolled deep-sea and coastal netting with by pollution and wild salmon's numbers are plural, followed by a plural verb.

Provide OA.

[AnjaliOberoi]

A number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting
B number of wild salmon is reduced because deep-sea and coastal netting is not controlled - parallelism issue
C numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting - parallelism issue
D wild salmon's numbers are reduced by deep-sea and coastal netting that is not controlled - awkward
E wild salmon's numbers have been reduced by uncontrolled deep-sea and coastal netting - correct

[AnuragRatna]

@phanikpk, @AnjaliOberoi
thank you guys for your prompt response.
You both are right.
OA is E.