A、To relieve its traffic congestion. B、To lessen its environmental problem. C、To guarantee drivers’ safety on the road. D、To imp

(5)India’s capital Delhi is ending a two-week trial that imposed major restrictions on private cars. Private cars with even and odd number plates were only allowed on alternate days during the experiment, which began on January 1. (6)The initiative is meant to curb the city’s air pollution. The trial took more than a third of the city’s three million private cars off the road, easing congestion. However, it is not clear whether it has helped to bring down pollution.
   Delhi has experienced hazardous levels of pollution this winter. The local government announced the scheme after a court ordered authorities to tackle pollution levels which stood at more than 10 times the World Health Organization’s safe limits. Authorities said the trial had resulted in a more than 50% drop in air pollution primarily caused by vehicular traffic.
   Emergency vehicles like ambulances, police cars, fire engines and taxis were exempt from the campaign, and single women were also allowed to drive their cars every day. The government hired private buses to provide shuttle services. (7)Schools were shut during the trial so their buses could also be used as public transport.
5. What is Delhi try doing recently?
6. What is the purpose of this experiment?
7. Why were school buses used as public transport during the experiment?