Ascientific law is
a. a universally accepted conclusion based on testing
b. always changing as new evidence is presented
c. based on new evolving theories, often debated in the scientific community
d. one step toward forming a theory

A. a universally accepted conclusion based on testing

Explanation:

A scientific law is a statement or a description of a naturally occurring phenomenon. It is often expressed in mathematical terms. Scientific laws are conclusions that came about after repeated experimentation and testing. They do not change by new discoveries instead, they are developed by adding into it. They are universally accepted in the scientific world. One thing that differentiates it from scientific theory is that it just shows the what, but does not explain the how and the why these phenomena occur.

A. a universally accepted conclusion based on testing

Explanation - Scientific theory is given as an answer to a natural happening in the earth but scientific laws are detailed idea of how nature will act under certain conditions. Theories are given after an experiment has been performed under controlled conditions.

Scientific theory cannot be changed to scientific laws and scientific laws cannot be changed to scientific theory. Scientific theories are broader in scope, and give overall clarifications of how nature functions and why it shows certain attributes.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).