OFFICIAL EXPLANATION
As surprising as it may seem, in the medium-long term Iceland is one of the places that are most likely to benefit from global warming.A. are most likely to benefit from
This answer correctly uses the plural verb are.
In the construction one of the + plural noun + who/which/that, the following verb is always plural.B. is most likely to benefit from
This answer choice is grammatically incorrect. The relative clause that are most likely to benefit from global warming describes the noun that appears immediately before it, namely, places. Since places is plural, the verb that follows it also needs to be plural. However, is is singular.
What helps us identify this question as a Relative Clause question as well as identify the mistake is the following Stop Sign:
one of the + plural noun + who/which/that
Whenever you see this Stop Sign, make sure that the following verb is plural.C. are likely to benefit from
While this answer choice is grammatically correct, it changes the meaning of the original sentence by the omission of the word most.D. is likely to benefit from
This answer choice is grammatically incorrect. The relative clause that are most likely to benefit from global warming describes the noun that appears immediately before it, namely, places. Since places is plural, the verb that follows it also needs to be plural. However, is is singular.
What helps us identify this question as a Relative Clause question as well as identify the mistake is the following Stop Sign:
one of the + plural noun + who/which/that
Whenever you see this Stop Sign, make sure that the following verb is plural.
In addition, the omission of the word most changes the meaning of the original sentence. E. are most likely to benefit
While this answer choice is grammatically correct, it is illogical as a result of the omission of the word from. Benefitting from global warming is different from benefitting global warming. This answer choice implies that global warming will benefit from several places, one of which is Iceland. This is not only different from the original meaning but also makes little sense.