How often an allele occurs in the gene pool is

Which of the following are energy solutions that release pollution into the air>

In a certain ecosystem owls are predators for mice. the owl population increases and they eat more mice this causes the mouse population to decrease what happens next? a.the birth of mice increases. b. the birth rate of owls increases c. the population of owls decreases d. the population of mice increases

Could someone me with number one you