In a stringed musical instrument, the sound frequency of a particular string can be increased by
a. tightening the string.
b. loosening the string.
c. lengthening the string.
d. increasing the string's thickness.

Which statement describes how favorable traits in a population relate to natural selection? they are the only traits that ever exist in the population. they build in the population over time. they are rarely passed on to offspring. they are found only in a few individuals within the population.