What did Muslims expand when they controlled part of Spain

Explanation:

Spain is the only western European nation to be controlled by Muslims, which segregated it from the rest of Europe during much of the Middle Ages. Under the Muslim Umayyad dynasty, Spain was the richest part of Europe and Muslim cities such as Grenada and Cordoba were much more advanced in science, medicine and the arts than their counterparts in Christian Europe.

The Muslim period in Spain is often described as a 'golden age' of learning where libraries, colleges, public baths were established and literature, poetry and architecture flourished. Both Muslims and non-Muslims made major contributions to this flowering of culture. In the 10th century, Cordoba, the capital of Umayyad Spain, was unrivalled in both East and the West for its wealth and civilisation.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain