Random changes in allele frequency in a population are usually called genetic drift. The reason why this is the answer is because it is a very specific word which is used to describe exactly that - random changes in allele frequency.
All the other cases; answers, here aren't correct and don't apply.
Answer: Hetrotypes are organisms (anything that lives) that can make it's own energy without absorbing it from other organisms. Example: Flowers, they get there energy from the sun, not from eating and absorbing other organisms.
Explanation:
