Given below are two statements: one is labeled as Assertion A  and the other is labeled as Reason R.

Assertion A: Polluted water may have a value of BOD of the order of 17 ppm.

Reason R: BOD is a measure of oxygen required to oxidize both the biodegradable and non-biodegradable organic material in water

In the light of the above statements, choose the most appropriate answer from the options given below.

Which of the following is not a common component of photochemical smog?

Sulphur dioxide is one of the components of polluted air. SO₂ is also a major contributor to acid rain. The correct and complete reaction to represent acid rain caused by SO₂ is

The BOD value of two samples of water are 4ppm and 18ppm, respectively and this indicates:
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Biochemical Oxygen Demand (BOD) is the amount of oxygen required (in ppm)
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Some tranquilizers are listed below. Which one from the following belongs to barbiturates?
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