The answer is B., Natural Selection.
Weather certainly doesn't change populations, and genes only caused individuals in a population to be slightly ( genetically-wise ) different from the others. It does cause change, but not change in the whole population over time.
Natural disasters don't change the populations over time either. Natural disasters only caused change in their environment, at most.
So, the only answer left is natural selection, and it makes sense too!
Natural selection is the process where the individuals with better traits suited to survive in that specific environment live on and give those good traits to their offspring.
The individuals with less suited traits to survive will die out, and will not be given an opportunity to reproduce and pass on their less suited traits, so over time, the population will increase of individuals with better suited traits to survive and the individuals with less suited traits will eventually die out, therefore making the entire population change.
Hope I helped you!
On his visit to the Galapagos Islands, Charles Darwin discovered several species of finches that varied from island to island, which helped him to develop his theory of natural selection.
C) Renal pelvis is the part of the kidney that acts as a funnel to pass the urine that is produced in several nephrons to the ureters.
