Question

read the text. then answer the questions.
seeking long - lived mammals, paleontologist finds two
that lasted at least 23 million years
by gayathri vaidyanathan
in all of earths history, which species of mammal survived for
the longest time?
benjamin burger, a paleontologist at utah state university, has
come up with two candidates that could not be more different: a
tiny shrewlike animal that ate insects and a giant relative of the
elephant that had a long snout and weighed more than four tons.
both lasted for at least 23 million years in the period after the
dinosaurs died out. when burger lowered the bar of survival to
20 million years, he found 19 types of mammals that lasted that
long.
all of these are what scientists call exceptional survivors; most
mammals are mere blips in the fossil record. the average
duration is just 1.7 million years. studying the tenacious
holdouts may help scientists figure out if there are any traits that

which sentence best summarizes a central idea of the text?
a burger discovered that smaller animals tended to live longer because they were able to
hide or hibernate.
some scientists disagree with burgers analysis about the factors involved in a species
overall survival rate.
c when burger studied the lifespan of ancient animals, he found 19 types of mammals that
lasted 20 million years.
d burger determined that the survival of a species largely depended on a combination of
genetic traits and a stable environment.

Explanation:

The text mainly talks about paleontologist Benjamin Burger finding two long - lived mammals. It also mentions that studying such long - lived species (exceptional survivors) can help understand traits related to species survival. Option D aligns with the overall idea as it summarizes Burger's determination about species survival depending on a combination of genetic traits and a stable environment. Option A is incorrect as the text doesn't focus on smaller animals living longer because of hiding/hibernating. Option B is not the central idea as the text is more about Burger's findings rather than scientists' disagreement. Option C is a detail (finding 19 types when survival bar was lowered) and not the central idea.

Answer:

D. Burger determined that the survival of a species largely depended on a combination of genetic traits and a stable environment.