Cloze text: Read the passage below and choose A, B, C or D to fill in each blank from 31 to 35

Many large cities around the world have struggled to keep up with the increase in traffic in recent times. Densely populated areas, growing car ownership, as well as narrow roads brought for much lower volumes of traffic all___(1)___ to this. In 1975, Singapore decided to introduce a congestion charge - a ___(2)___ paid by drivers entering the most traffic-heavy zones of the city. London introduced a congestion charge in 2003.
Public opinion was initially opposed to the idea, ___(3)___people soon became more supportive of the scheme. Despite this, its first decade brought mixed success, and the ___(4)___ of cars in the city fell by only 10%. However, the scheme proved massively profitable, ___(5)___ allowed the city council to invest in other measures aimed at improving traffic conditions in London. These included cycle lanes, pedestrianized areas and better road surfaces.
(Adapted from Oxford Exam Trainer by Helen Weale)