Which of the following is a non-point source of water pollution?

Why is $CNG$ considered a better fuel than diesel?
$(a)$ It cannot be adulterated.
$(b)$ It takes less time to fill the fuel tank.
$(c)$ It burns more efficiently.
$(d)$ It is cheaper.
$(e)$ It is less inflammable.
Choose the most appropriate answer from the options given below:

Due to biomagnification,if the concentration of $DDT$ in water is $0.003 \, ppm$,what will be the concentration of $DDT$ in zooplankton,small fish,large fish,and fish-eating birds,respectively?

Identify $X$ and $Y$ from the figure representing an Electrostatic Precipitator:
$X-Y$

What problem arises if irrigation is provided for a long time in fields?

Carbon monoxide $(CO)$ is a pollutant because...