Pneumoconiosis afflicts the workers who works mainly in :

Pneumoconiosis commonly refers to the dust-induced fibrotic lung disease seen in coal miners, historically known as “black lung,” caused by deposition of coal dust in the lungs of coal workers [1]. Authoritative occupational-health sources describe coal workers’ pneumoconiosis as developing after inhalation of airborne coal dust and note it is most common among coal miners, producing progressive scarring and impaired breathing [2]. While other pneumoconioses (e.g., silicosis, asbestosis) occur with exposures in different industries, the classic association tested in basic occupational-health questions is coal-mining workers and coal dust–related pneumoconiosis. Therefore the correct option is 2 (Coal mining industry).

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > e) Pneumoconiosis > p. 416
2. [2] https://www.lung.org/lung-health-diseases/lung-disease-lookup/black-lung