Answer:
The correct answer is option A. "directional selection".
Explanation:
Directional selection is a type of natural selection at which traits with extreme characteristics are selected over traits with medium characteristics. In this case, a long-term climatic change resulted in all seeds that are the fountain of food for finch becoming hard. This will result in a directional selection on bill size in the finch population, where large-billed birds will be selected over small and medium-billed birds.
Independent Variables can be manipulated, and a Dependent Variable are observed and measured. Another way to say it is that the Independent variables change to get different results while the Dependent variables never change because you are trying to see what causes it to change
Science subject demonstrate observation
Social welfare department observation
