Although she faced many obstacles in her research, Dr. Franklin is widely recognized for one major ___________ discovering the double-helix structure of DNA.
4
writingWhich choice completes the text so that it conforms to the conventions of Standard English?
A
achievement:
B
achievement,
C
achievement;
D
achievement
Correct Answer: A
Choice A is the best answer. A colon is used to introduce the specific example (discovering the double-helix...) that defines the "major achievement."
Choice B is incorrect because a comma is too weak. Choice C is incorrect because a semicolon separates independent clauses. Choice D is incorrect because punctuation is needed to separate the noun from its appositive definition.