Q. Consider the following statements:
1.Neurotoxins are poisonous substances which can directly affect the nervous system.
2.Methane has a pungent odour.
3.Chemical oxidation is done to remove gases such as hydrogen sulphide from wastewater..
Which of the statements given above are correct?

[A] 1 and 2 only

[B] 2 and 3 only

[C] 1 and 3 only

[D] 1, 2 and 3

Answer: C
Notes:

Explanation –

Statement 1 and 3 are correct. Neurotoxins are poisonous substances which can directly affect the nervous system. Chemical oxidation is done to remove gases such as hydrogen sulphide from wastewater.

Statement 2 is incorrect. Methane and carbon monoxide are odourless gases.

Source: The Indian Express