Five jumbled up sentences (labelled A,B,C,D and E ), related to a topic, are given below. Four of them can be put together to form a coherent paragraph. Identify the odd sentence and key in the number of that sentence as your answer.

1. Urbanites also have more and better options for getting around: Uber is ubiquitous; easy-to-rent dockless bicycles are spreading; battery-powered scooters will be next.

2. When more people use buses or trains the service usually improves because public-transport agencies run more buses and trains.

3. Worsening services on public transport, terrorist attacks in some urban metros and a rise in fares have been blamed for this trend.

4. It seems more likely that public transport is being squeezed structurally as people's need to travel is diminishing as a result of smartphones, videoconferencing, online shopping and so on.

5. There has been a puzzling decline in the use of urban public transport in many countries in the west, despite the growth in urban populations and rising employment.