You have to measure the distance between them
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:
On a biological level, the main difference is that bacteria and free-living cells can live inside or outside a body, while viruses are a non-living collection of molocules that need a host to survive.
Explanation:
