Which of the following is a possible reason for migration?
a. microevolution
b. diminished food supply
c. increased ecosystem stability
d. macroevolution

Well, migration means to move to one place or another so I believe it is B. I think it is possible because that was one of the reasons nomads, people who move one place to another migrated. They had no food so they kept on moving until they found food. And I guess it was just a cycle. I hope this helps:)

Why one might choose to migrate is a very complex topic. When whole groups are migrating from one country, this tells us that there is something wrong with the situation in the original country. A possible cause for migration would for example be a diminished food supply - B.

If in a certain country we would be witnessing lack of food, we would have astrong reason why we would want to migrate. 

Answer/// absolute and unchanging laws;

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.