Explain how natural selection can impact allele frequencies (amount of traits seen) of a population

Natural selection can cause microevolution (change in allele frequencies), with fitness-increasing alleles becoming more common in the population. ... Natural selection can act on traits determined by alternative alleles of a single gene, or on polygenic traits (traits determined by many genes).

Explanation:

Natural selection causes the most favourable traits to become more common and therefore appear in larger frequencies. That means unfavourable alleles will be seen in smaller frequencies as the carrier is more likely to die before reproducing and passing on their genes

The correct answer is A