Unlike all the other mammal species whose olfactory receptors, which

Unlike all the other mammal species whose olfactory receptors, which detect smell, were studied, the African elephants use nearly 2,000 olfactory genes to smell various objects, which in turn detect their odor.

Meaning of the sentence: Olfactory receptors of various mammal species were studied. In contrast to other mammal species that were studied, African elephant uses nearly 2000 olfactory genes to smell various object, and in turn detect the objects' odor.

Error(s):
1) modifier error: the underlined portion suggests that the objects in turn detect their odor.
2) pronoun antecedent ambiguity: pronoun their refers to object, or genes is not clear per the construction of the sentence. However, their should refer to the various objects which are smelled by the elephants.

A. objects, which in turn detect
1) modifier error: the underlined portion suggests that the objects in turn detect their odor.
2) pronoun antecedent ambiguity: pronoun their refers to object, or genes is not clear per the construction of the sentence. However, their should refer to the various objects which are smelled by the elephant.

B. objects, and they will detect
not clear who will detect whose odor

C. objects, resulting in detecting
the use of nearly 2000 olfactory genes doesn't itself result in detection of the odor. The sentence intends to convey the meaning that the African elephant detects the objects'odor using numerous olfactory genes.

D. objects that result in detecting
modifier error: the underlined portion suggests that the objects in turn detect their odor.

E. objects and thereby detect
It correctly conveys the intended meaning.

Answer: E