Which of the following best describes informal settlements often seen in urban regions?

Informal settlements are often characterized as shanty towns, which are typically unplanned and constructed using makeshift materials. These areas arise in urban regions where rapid population growth, often due to migration from rural areas, outpaces the availability of formal housing. Shanty towns tend to lack basic infrastructure such as sanitation, water supply, and electricity, leading to challenging living conditions.

In contrast, luxury apartments represent high-end housing designed for wealthier residents, while planned neighborhoods are systematically designed with organized streets, services, and amenities. Rural villages, on the other hand, are found outside urban areas and usually have more space and different characteristics from informal settlements. Therefore, the defining attributes of informal settlements align closely with those found in shanty towns, making this option accurate.