Which statement describes a Muslim achievement in science and mathematics?

The following are contributions of Muslims to Mathematics:

A. Muslim scholars collected and translated the work of scholars frommany parts of the world.

B. Baghdad was a center of learning with a university and library.

C. Al-Khwarizmi simplified Hindu numerals to make the system of numbers we use today.

This was known to be a big part during the Golden Age of Islam in the 9th and 10th centuries. They developed a lot of concepts in Trigonometry, Geometry, and Algebra.