For each hour of production, a certain factory requires 1 assembly line worker for every 25 units to be produced in that hour.

B) 12 + 2N

Explanation:

The company requires 1 assembly line worker for every 25 units it produces per hour, so it will require 2 assembly line workers for every 50 units. The number of managers is fixed = 12.

therefore the total number of workers = 12 (fixed managers) + 2N (assembly line workers for each for every 50 units) = 12 + 2N