The correct option is B The number zero
The Arabs made outstanding contributions in the medieval world, which are used even in the modern era like Algebra. Muhammad ibn Musa al-Khwarizmi's book on the calculation with Hindu numerals was principally responsible for diffusing the Indian system of numeration in the Islamic land and the West. The new system was far superior as it allowed people to multiply and divide easily and check their work. In addition to this, al-Khwarizmi also wrote a revolutionary book on resolving quadratic equations. The number 'Zero' was a concept conceived by Aryabhatta, an Indian astronomer and mathematician.