The residential areas of the least choice, dilapidated houses, poor hygienic conditions, poor ventilation, lack of basic amenities, like drinking water, light and toilet facilities, etc. represent which of the following?

Slum

The correct answer is Option (3) → Slum

Slums are residential areas characterized by poor living conditions, including dilapidated houses, lack of sanitation, inadequate drinking water, poor ventilation, and absence of basic amenities. These areas are typically inhabited by the urban poor.