siddhans wrote:
Why is A wrong in 1?
The last line of the para says this:- The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.
I know my answer may not matter now to you, still I am happy to reply.
The passage does not intend to say that the research that seems promising was done on the drug rather the research was for the entire process.
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