What evidence do historians use to show that the maya had advanced knowledge of astronomy

The choices can be found elsewhere and as follows:

a. Huge temples aligned to four cardinal directions

b. The maya developed a 365 day solar calendar

c. The maya had identified all the planets in the solar system

d. Maya priests invented concept of zero

I think the correct answer is option B. The evidence that historians use to show that the maya had advanced knowledge of astronomy is that the maya developed a 365 day solar calendar.