How can natural selection acting on one trait result in

geneticdrift of other genes?

The evolution of a species is driven by many evolutionary mechanisms two of which are: natural selection and the genetic drift.

The natural selection selects the species or the alleles which increase the reproductive success of the species in a given environment whereas the genetic drift cause evolution by randomly selecting the alleles based on the sampling error. The genetic drift selects the alleles or species by chance and not on the beneficial and harmful basis.

In the given question, If natural selection favours the one trait of the species on the basis if it provides fitness then it could result in a genetic drift of alleles of another trait as it is purely based on the chance.