In order to scientifically validate a sample, it is necessary that,
The entire population under study should be considered to obtain an average or a mean data. If only a part of the population is considered then the result obtained would be a biased one. A biased data will not represent the entire population and so it would be incorrect.
The sample choice done must be at random covering all the areas of the population to get the accurate result. This is because random selection lowers the possibility of getting biased.
Answer: C. Ranges and niches are moving farther North
Explanation:
Animals are moving north toward the North Pole to escape the heat. Towards the poles, the temperatures get colder. Because of global warming, the temperature zones move out towards the poles.
