HELP ME ...GENERAL READING

[dmsaussie]

Dust levels are controlled by spraying roads and stockpiles, and water pollution is controlled by carefully separating clean water runoff from runoff which contains sediments or salt from mine workings. The latter is treated and re-used for dust suppression
To control dust at mine sites, mining companies often use
A chemicals which may be toxic.
B topsoil taken from the site before mining.
C fresh water from nearby dams.
D runoff water containing sediments

Help me to figure out the correct answer

[dmsaussie]

ANy ideas guys

[andytruong1202]

Dust levels are controlled by spraying roads and stockpiles, and water pollution is controlled by carefully separating clean water runoff from runoff which contains sediments or salt from mine workings. The latter is treated and re-used for dust suppression
To control dust at mine sites, mining companies often use
A chemicals which may be toxic.
B topsoil taken from the site before mining.
C fresh water from nearby dams.
D runoff water containing sediments

Help me to figure out the correct answer

I'd choose D. You can easily cross out A, B. It'll then leave you only 2 options: C and D. Then "the latter is treated and re-used"; but there's no need to treat fresh water so the answer should be D.

[dmsaussie]

Yes , thats correct , i can narrow down the options in the first cut