Answer:
<em>D. All of the above </em>
Explanation:
<span>ASEAN is an Association of Southeast Asian Nations - a multination association that has as its aim an economic cooperation between Southeast Asian countries (such as Thailand). This association did not arise as a response to external factors, so any reason connected to externam factors would not apply - such as the reliance on some external powers (such as the US). It is focused on the cooperation between the members only - not an external association.</span>
One of the major elements of natural selection is that all species have genetic variation. Natural selection is a process when organisms adapt better to their environment. It is an essential key in evolution. There is a change in phenotype of a population over time.
Every year the farmer was taking care of his ice field, keep it clean and clear of all the unnecessary shrubs and then reuse the debris to fertile the soil again and then grow rice again. But since he fell sick, there is no one to take care of his rice field which will leads to the growth of unnecessary plants and weeds in it.
There will grow wild plants and shrubs which will contaminate the rice field.
It is important because the results would not be reliable since other variables you are not testing could have been in affect.
Hope this helps(;
