Which concept did the maya understand before europeans did?

That would be the concept of zero, which the dates to around 1200AD in Europe. This doesn't mean it wasn't known in the Middle East and Asia. Evidence of the concept of zero in the Maya realm appears around 200BC-200AD.

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.

it should be d or b but i'm sure it's d