Question

arabic mathematics revolutionized european economies by introducing:
a the concept of 1.
b the concept of a decimal.
c arabic numerals, which replaced roman numerals.
d imaginary numbers.
e the concept of long division.

Explanation:

Arabic numerals (0 - 9) replaced Roman numerals. They made arithmetic operations (like addition, subtraction, multiplication, and division) much easier. This was crucial for trade, accounting, and economic activities in Europe. The concept of 1 was known before. The decimal concept (though related to Arabic numerals in a sense of base - 10) is not the most impactful in terms of economic revolution compared to the numerals themselves. Long division is an operation that became easier with Arabic numerals but it was the numerals that were the fundamental introduction. Imaginary numbers are more of a higher - level mathematical concept and not directly related to economic revolution in the context of replacing an existing numeral system.

Answer:

C. Arabic numerals, which replaced Roman numerals.