Help ASAP PLZ! correct me if am wrong ty boys and girls

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Which of the following terms would bb represent in an organism? a.phenotype b.genotype c.genetics

Aclient is to receive rifampin. which would be most important for the nurse to include in the teaching plan for this client?