Eli Eisenberg, a genetics expert at Tel Aviv University in Israel, recently discovered that ______ have a special genetic ability
called RNA editing that confers evolutionary advantages.
cephalopods, ocean dwellers that include the squid, the octopus, and the cuttleﬁsh
cephalopods—ocean dwellers—that include the squid, the octopus, and the cuttleﬁsh,
cephalopods, ocean dwellers that include: the squid, the octopus, and the cuttleﬁsh,
cephalopods—ocean dwellers that include the squid, the octopus, and the cuttleﬁsh—
Choice D is the best answer. The convention being tested is the punctuation of a supplementary element within a sentence.
In this choice, the dash after “cephalopods” pairs with the dash after “cuttleﬁsh” to clearly separate the supplementary
element “ocean dwellers that include the squid, the octopus, and the cuttleﬁsh” from the rest of the sentence. This
supplementary element functions to explain what cephalopds are, and the pair of dashes indicates that this element could
be removed without affecting the grammatical coherence of the sentence.
Choice A is incorrect because it fails to use appropriate punctuation to separate the supplementary element that explains
what cephalopods are from the rest of the sentence. Choice B is incorrect because it fails to use appropriate punctuation to
separate the supplementary element that explains what cephalopods are from the rest of the sentence. Choice C is incorrect
because it fails to use appropriate punctuation to separate the supplementary element that explains what cephalopods are
from the rest of the sentence.