The MegaTek Corporation is displaying its distribution of employees by department in a circle graph. The size of each sector of the graph representing a department is proportional to the percentage of total employees in that department. If the section of the circle graph representing the manufacturing department takes up 72° of the circle, what percentage of MegaTek employees are in manufacturing ？（）
A. 20%
B. 25%
C. 30%
D. 35%
E. 72%