Narrative 17-2 For More Than a Century, the City of London, England

Narrative 17-2
For more than a century, the city of London, England, has had the worst traffic in Europe. Half the time is spent at a standstill, and the average speed is 9 mph, down from 12 mph in 1903 when traffic consisted of horses and carriages. To improve traffic, London's mayor has imposed a "Congestion Zone" fee of £5 per day for any vehicle that enters the eight square miles of central London between 7 a.m. and 6:30 p.m. on weekdays. Drivers who enter the zone but don't pay are fined from £50 to £125.
First, 688 cameras were used in 203 locations to take accurate pictures of vehicles entering the zone. In general, the cameras are only 90 percent accurate in reading the licence plate numbers on the cars. But with 688 cameras in total, multiple pictures are taken of each car, and partial pictures of licence plates are matched with complete pictures, with the former discarded and the latter retained.
Next, the pictures from the cameras are sent via a dedicated fibre-optic cable to an "image management store." An "image management store" is basically a huge farm of networked, redundant servers. If one server goes down, multiple backup servers run live with the same data. Doing this was needed because the city anticipated processing one million pictures a day.
Once the pictures are snapped, transported via fibre-optic cable, and placed in the "image management store," the next step is "reading" the licence plate in the picture, converting it to readable text, and matching licence plate records stored in government databases. Transport of London uses software that scans digitized documents into ASCII text and then matches and compares multiple pictures of the same licence plate. For example, imagine that a licence plate is 12345678 and that the congestion cameras get three partial pictures-12345, 34567, and 5678-and one complete picture, 12345678. The software has to interpret that all four pictures were of the same vehicle; then, it has to select the last picture, 12345678, not the partial pictures, when converting the picture to text. Finally, once the licence plate is converted to text, its number is then matched with an existing licence plate in a government database. At that point, "Congestion Zone" charges are linked with whoever owns the vehicle.
-Refer to the Narrative 17-2..Which kind of technology is used to turn the licence plate number captured by a photograph into readable text that matches licence plate records already stored in government databases?

A) virtual private networks
B) SSL encryption
C) private encryption codes
D) optical character recognition software