Which of the following is a photochemical reaction product?

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

Assertion : Organochlorine pesticides are organic compounds that have been chlorinated.
Reason : Fenitrothion is one of the organochlorine pesticides.

Assertion: Excess of nitrates in drinking water is harmful for infants.
Reason: Nitrates are responsible for blue baby syndrome.

According to the Central Pollution Control Board $(CPCB)$,particles that are responsible for causing great harm to human health are of diameter

Foul smell in the water of tanks,ponds,etc.,is due to: