Which choice completes the text so that it conforms to the conventions of Standard English?
A
added, whenever
B
added; whenever
C
added. Whenever
D
added whenever
Explanation
Correct answer: D.
Choice D is the best answer. The convention being tested is punctuation between a verb and a preposition. When, as in this case, a verb (“is added”) is immediately followed by a preposition (“whenever”), no punctuation is needed.
Why the other choices are wrong
Choice A
Choice A is incorrect because no punctuation is needed between the verb and the preposition.
Choice B
Choice B is incorrect because no punctuation is needed between the verb and the preposition.
Choice C
Choice C is incorrect because no punctuation is needed between the verb and the preposition.