A. …the African elephants use nearly 2,000 olfactory genes to smell various objects, which in turn detect their odor.which refers to
various objects and illogically means that various objects detect their (objects') odor. However, not various objects themselves but the elephants detect the odor of various objects.
B. …the African elephants use nearly 2,000 olfactory genes to smell various objects, and they will detect their odor. When universal truth is meant we normally use present simple, not future tense.
In a single clause
they refers to elephants while
their refers to objects. That’s not ideal or good or even normal. However, there is actually one
OG problem that accepts such usage because all other answers choices also have the same structure. The explanation was that logically we can understand to what
they and
their are referring to, so such pronoun ambiguity is acceptable. Here we definitely have a better choice, so let’s move on.
C. …the African elephants use nearly 2,000 olfactory genes to smell various objects, resulting in detecting their odor.Comma+ resulting in is an adverbial modifier describing
use and
elephants. The sentence means that when elephants use genes they (elephants) result in detecting the odor. Saying that elephants result in the detection of odor is nonsensical. We are not talking about two different actions, one resulting in another, but we are talking about a single action (smelling) with two descriptions.
resulting in the detection is superior to
resulting in detecting, because the latter is not so academic.
D. …the African elephants use nearly 2,000 olfactory genes to smell various objects that result in detecting their odor.that may refer to
objects or
genes. In both cases the meaning is nonsensical. As in C,
result in detecting is not academic.
E. …the African elephants use nearly 2,000 olfactory genes to smell various objects and thereby detect their odor.Elephants use genes and thereby detect – here
thereby conveys the correct meaning. We are talking not about two different actions, but about one action – smelling. We just give two descriptions of a single action, thus saying that elephants use genes and thereby detect is correct.
Hence
E _________________