The national insurance firm offers four tiers of coverage plans;
buyers can choose among bronze, silver, gold, and platinum plans, there are no plans that offer greater coverage than the platinum tier or less than the bronze.
(A) buyers can choose among bronze, silver, gold, and platinum plans, there are
incorrect - run on sentence - buyers can choose......, there are no plans....
(B) because buyers can choose bronze, silver, gold, or platinum, there are
incorrect - the sentence doesn't makes any sense. It implies that because the buyers can choose either of the four plans, so there are no other plans.
(C) however, buyers can choose among bronze, silver, gold, and platinum, and
incorrect - buyers can choose among bronze,.... and platinum(what? - plans), and no plans ..(that clause)
parallelism issue - clause, and phrase +modifier
(D) buyers can choose among bronze, silver, gold, platinum plans, but
incorrect - list bronze, silver, gold, platinum plans should have (,and) before platinum plans. Also the meaning of the sentence is awkward as it implies that buyers can choose among the four available plans, but no plans ...(that clause )
Also, parallelism issue - clause, but phrase +modifier
(E) although buyers can choose among bronze, silver, gold, and platinum plans, there are
Correct - Dependent clause, Independent clause
The intended meaning is clear and concise.
Answer E