Modern inventions such as the pneumatic drill
may seem to have improved the work conditions
of manual laborers, but in fact, have increased
the incidence of health hazards such as silicosis
because it has aggravated the dust hazard
involved in excavation and demolition.

(A) have increased the incidence of health
hazards such as silicosis because it has
aggravated the dust hazard
(B) has increased the incidence of health
hazards such as silicosis because it has
aggravated the dust hazard
(C) have increased the incidence of health
hazards such as silicosis because they
have aggravated the dust hazard
(D) increased the incidence of health hazards
such as silicosis because they aggravated
the dust hazard
(E) increased the incidence of health hazards
such as silicosis because of aggravating
the dust hazard

OA affter discussion.
(Can we please follow the format as i followed in the subject - Topic_source of the question)