Nearly all mammals have seven cervical (neck) vertebrae. this fact implies that
a.
all mammals have to stretch their necks to obtain food.
b.
all animals can turn their heads the same amount.
c.
all mammals descended from a common ancestor.
d.
predators prefer to eat animals with either six or eight cervical vertebrae.

The correct answer is option c- nearly all mammals descended from common ancestors.

Human cervical vertebra consists of 7 bones from top to bottom:

-C1

-C2

-C3

-C4

-C5

-C6

-C7

Cervical vertebra are located just below the skull are the neck bones that control the neck movements. In humans, cervical vertebrae are the smallest of all vertebrae. In different organisms, the size of these vertebrae vary.

answer: the answer is b

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.