Question

may shed light on animal behavior\
scientists have pieced together the first - ever fossil of a pregnant plesiosaur, a giant mesozoic sea reptile from the cretaceous era, with an embryo still inside.
the animal, which roamed the seas 78 - million years ago, is about 15 - feet long — the length of a minibus — and bones indicate that the baby plesiosaur would have been as long as six feet when born.
the finding, published in the online edition of the journal science on thursday, is definitive evidence that the giant sea creature gave birth to single, live offspring, rather than laying eggs, like most reptiles, says paleontologist and lead author f. robin okeefe. this reproductive behavior also indicates that the animals were gregarious social creatures that cared for their young, similar to toothed whales or dolphins, according to the paper.
which statement provides an explanation about the impact of specific word choices on the overall tone of the text?
(1 point)
the author quotes reputable sources familiar with the subject using denotation to establish a formal tone in the text.
the author draws a comparison to contemporary mammals using words with a positive connotation to establish a friendly tone in the text.
the author quotes reputable sources unfamiliar with paleontology using denotation to establish a curious tone in the text.
the author draws a comparison between the plesiosaur to other reptiles of the time using words with a negative connotation to establish an informal tone

Explanation:

Denotation refers to the literal meaning of words. When the author quotes reputable sources (paleontologist F. Robin O'Keefe, journal Science) familiar with the subject (paleontology, animal behavior), using the literal meaning of words (denotation) helps in presenting information in a straightforward, objective, and formal way. This is typical of scientific/academic writing which aims for precision and a formal tone.
The second option: There's no positive - connotation - based comparison to contemporary mammals in the text. The third option: The sources are familiar with paleontology. The fourth option: There's no negative - connotation - based comparison to other reptiles, and the tone is formal, not informal.

Answer:

The author quotes reputable sources familiar with the subject using denotation to establish a formal tone in the text.