Answer:
c) Polls are the least reliable way to measure opinon
Explanation:
Opinion polls or poll is the term term used to sample the opinion or take survey of a small population from a large population.
The reason opinion polls are not always encouraged or the best form of data collection or research is because the polls are not always reliable.
Most times individual who don't have better knowledge about an issue end up giving an opinion about it.
It uses a subset to determine the opinion of a population.
These reason are why opinion polls are not reliable.
Answer: E - year only if non-OPEC nations, including Norway, Mexico, and Russia, trim output
Explanation: From the above question, we are looking for the best constructed sentence among the options given.
Looking through all the options, A and B with the phrase ...'but only if' is wrong.
Options C and D has some grammatical issues at the end of each statement which made them both not correct.
The only option we are left with is the option E which states that 'year only if non-OPEC nations, including Norway, Mexico, and Russia, trim output' is correct.