Minamata disease was caused due to the consumption of

Biochemical oxygen demand $(BOD)$ in a river water

Which of the following is an effect of $SO_2$ on plants?

What is the major drawback of $DDT$ as an insecticide?

Why is $CNG$ considered a better fuel than diesel/petrol?
$I.$ $CNG$ burns most efficiently without leaving any unburnt remnant behind.
$II.$ $CNG$ is cheaper than petrol or diesel.
$III.$ $CNG$ cannot be siphoned off by thieves and adulterated like petrol or diesel.
Which of the statements given above are correct?

$BHC$ and $DDT$ belong to which class of pesticides?