C. industrial revolution is the correct answer
An astrolabe is a primitive angle-measuring tool. It can be used to - very in-exactly! - measure the altitude above the horizon of a celestial body like the Sun, Moon or Polaris in order to calculate your position.
Medieval gunners used the astrolabe to calculate the height of towers and buildings, in order to more accurately aim their cannons.
52.85 - 9.09
1. Round '52.85' to the nearest one
52.85 ⇒ 52.9
2. Round '9.09' to the nearest one
9.09 ⇒ 9.1
3. Subtract
52.9 - 9.1 = 43.8
The answer to the question is A.
