Complete each sentence choosing the correct option
In 2017, barley was ranked fourth among grains in quantity produced (149 million tonnes) behind maize, rice and wheat.
The wild ancestor of domesticated barley, Hordeum vulgare subsp. spontaneum, is abundant in grasslands and woodlands throughout the Fertile Crescent area of Western Asia and northeast Africa, and is abundant in disturbed habitats, roadsides, and orchards. Outside this region, the wild barley is less common and is usually found in disturbed habitats.However, in a study of genome-wide diversity markers, Tibet was found to be an additional center of domestication of cultivated barley.