685. The 19th-century proponents of the school of thought known as mechanism held that life process are not the products of some mysterious life force, but are the same chemical and physical processes that operate in inorganic systems, which is still a subject of debate between biologists today.

(A) systems, which is still a subject of debate between
(B) systems, which are still debated between
(C) systems still debated among
(D) systems, a theory still debated by
(E) systems, a theory still debated between

Solution:

Idioms + Modifiers

In A and B, “which” incorrectly refers to “inorganic system”.
In C, “inorganic systems still debated among biologists today” changes the meaning.
In E, “debated between biologists” is incorrect. “Between X and Y” is idiomatic.
In D, “still debated by biologists” rectifies the error with E. Hence, D is the best choice.

​Sentence Correction - 1000 Questions with Solution: