Which of the following statements regarding fins on fishes is true?
a. fins evolved so that fish could swim better.
b. fins resulted from a mutation caused by a movement from land to water.
c. fins are an adaptation that aid in swimming.
d. fins came about because animals couldn't live in water without them.

The answer is B

Explanation:

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.