Sentence Correction

It was an increase in reported cases of malaria along the Gulf Coast that in 1921 led the health authorities' granting a permit for experimentation with human subjects to the group that later would be called by the name of Unimedco.

　　(A) authorities' granting a permit for experimentation with human subjects to the group that later would be called by the name of

　　(B) authorities' granting a permit for experimentation with human subjects to the group that later to be called by the name of

　　(C) authorities' granting a permit for experimentation using human subjects to the group that later would be called by the name of

　　(D) authorities to grant a permit for human experimentation to the group later called

　　(E) authorities to grant a permit for human experimentation to the group that later would be called by the name of

IMO: C

IMO D

I'll go with D, although I'm not very confident. What's the OA? And could maybe an expert comment?

(D) seems fine.

A and B both use the expression "led...for" which doesn't make sense in this context. The sentence is saying that the increase in malaria cases caused the health authorities to take action; we should use "led to" to make this clear.

C does not give us a linking preposition at all. ("led authorities' granting a permit...")

D and E both have "led...to...", which works. E is much wordier: "that later would be called by the name of" as compared to D's "later called." D is the better choice.

OA is D

IMO D