The correct option is C Schools
The construction activities take place every day as per need such as the construction of buildings, bridges, dams, roads etc. For the construction, different types of equipment are used that produce enough noise.
A large number of vehicles on roads, aeroplanes flying over houses, underground trains produce heavy noise and people get it difficult to get accustomed to that. The high noise leads to a situation wherein normal person lose the ability to hear properly. But schools are not the causes of noise pollution. Thus, the correct answer is option D.