SAT Transitions Question

Around 6,000 years ago, humans in eastern Europe began the process of domesticating the wild horse(Equus ferus). wild horses were domesticated through selective breeding to be used for transportation and for plowing fields, among other things. The present-day result of this millennia-long process is Equus caballus, a distinct species commonly known as the domestic horse. Which choice completes the text with the most logical transition?