Taste buds are onion-shaped structures with between 50 and 100 taste cells, each of them has fingerlike projections poking through the opening located at the top of the taste bud called the taste pore. 



(A) them has fingerlike projections poking through the opening located at the top of the taste bud called the taste pore 

The pronoun “them” does not have a clear antecedent. 

Two independent clauses connected using a comma gives us a comma splice or a run on sentence. 

Called the taste pore refers to/modifies the opening and hence must be placed next to “opening”.

Eliminate. 


(B) them that have fingerlike projections that poke through an opening located at the top of the taste bud, which they call the taste pore 

The pronoun “them” does not have a clear antecedent. 

We need to use the singular verb- “has” for the singular subject- “each of them”

which they call - no clear referent.

Which refers to taste bud. Incorrect. It is the opening that is called the taste pore. 


(C) which has fingerlike projections poking through the opening, called the taste pore, located at the top of taste bud 

“Which” refers to taste cells.

Called the taste pore modifies “the opening”


(D) which having fingerlike projections that poke through an opening, which is called the taste pore, located at the top of the taste bud 

Having functions as a participle and not as a verb in the sentence. This leaves us with a sentence fragment.


(E) which have fingerlike projections that are poking through an opening located at the top of the taste bud called the taste pore

We need to use the singular verb “has” for the singular subject “each of which”

Called the taste pore refers to/modifies the opening and hence must be placed next to “opening”.

Eliminate.