Answer:
Explanation:
The answer is C.
He may have made a contribution to D. There are over 360 different proofs for the Pythagorean theorem but that would not be his major contribution.
B may also be true, but if it is, he is not noted for it.
A not the Chinese system.
His main contribution was in the solution of equations like
y = 2x^2 + 20x + 12 = 2(x^2 + 10x + 25) - 12 = 2(x + 5) - 62 (completing the square) which we teach in the lower grades now, but when you learn something about the number system used, you realize that any contribution is remarkable.
