Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Lagos, Nigeria (CNN) Lagos, one of Africa's most populous cities, has been hit by torrential downpour and thunderstorms over the weekend that has left many parts of the city flooded. Residents in the Lekki and Victoria Island suburbs woke up on Saturday morning to flooding in their homes and their cars submerged under water. One brave resident took to swimming in the infested waters on Lekki road, an affluent suburb that is home to some of the most expensive real estate in the coastal city. A crocodile was spotted along Chevron Drive in the same neighborhood. Another was spotted kayaking across Ahmadu Bello Way, Victoria Island, a usually bustling business district.Lagos, one of Africa's most populous cities has been hit by torrential downpourPoor drainage systems and weak urban planning have compounded effects of the rainfall 
 Question:The past 40 years has transformed _, infamous for its heavy traffic and poor air quality.

Lagos