Which statement best describes how humans select for wrinkly skin in Chinese Shar Peis?

By mating a very wrinkly female and non-wrinkly male so they have the best chance of passing on the gene for wrinkly skin.
By inserting a gene for wrinkly skin into every Shar Pei puppy.
By mutating the DNA of one Shar Pei, hoping they will pass on the mutated trait to their offspring.

By mating Shar Peis that exhibit wrinkly skin in order to increase the likelihood of passing on the trait to their offspring.