Eliminate A, B, C; "the authorities' granting a permit for experimentation" is awkward. Choice E is wordy; "called by the name of" is unnecessary; we can just use "called."

This leaves us with D.

IMO

Redundancy leading to wordiness in E can be avoided

called <=> by the name of

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
i don't think authorities’ granting is the right usage. called by the name of is redundant.
(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
called by the name of is redundant


My answer: D