. Which statement best expresses the central idea in the article? A. Scientists have discovered a way to prevent genetic defects in babies, but some believe genetic development should be left to nature
B. Scientists have discovered a way to prevent genetic defects in babies, but some worry that the process could be used for great economic gain
C. Scientists have discovered a way to prevent genetic defects in babies, but the method is against many families’ religions
D. Scientists have discovered a way to prevent genetic defects in babies, but the process is still very risky

I believe the Answer is D

Explanation:

Mainly because b, c, arent very logical and A is also a decent choice but i believe d is the answer

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

i dont know this but ask your teacher for !