D. a viral disease because it is known and unknown and spreads.
A biological theory, like the theory of evolution, that is widely accepted and supported by so many observations and experiments may be referred to as a principle or a law.
<h3>What is a Law?</h3>
This refers to statements which describes or predict a range of natural phenomena as a result of repeated experiments which has been performed and the authenticity has been prove by peers and other individuals.
A law is also referred to as principle and has been observed to be always true unlike due to the repeated scientific methods being done approving of its validity thereby making law the correct choice.
Read more about Law here brainly.com/question/820417
#SPJ1
I think B is the answer The Clean Air Act That prevented air pollution and protected the ozone layer as well as promote public health. This act gave Enviromen. Protection Agency the power to take effective action fighting environmental air pollution
