How would our groundwater be endangered according to the fifth paragraph?
A.
It would be endangered by manufacturing factories.
B.
It would be endangered by leakage from masses of hazardous substances that were buried underground or dumped in improper storage sites.
C.
It would be endangered by careless day-to-day disposal of wastes from thousands of individual sources.
D.
It would be endangered by substances which are thrown away carelessly by companies.