IQAir Air Quality Index

Current Context: The IQAir Air Quality Index was released, which gives the ranks for the cities in the world as per their pollution content in the air.

• The IQAir is the Switzerland-based climate group.
• Indian cities namely, Delhi, Kolkata, and Mumbai are the top ten most polluted cities of the world.
• Among these, Delhi has topped with the AQI at 556.
• The Kolkata and Mumbai were at AQI of 177 and 169, respectively, at fourth and sixth position in the list.
• An AQI between zero and 50 was considered to be ‘good’; an AQI between 51 and 100 was considered to be ‘satisfactory’; similarly, AQI 101 and 200 (‘moderate’); 201 and 300 (‘poor’); 301 and 400 (‘very poor’); then 401 and between 500 (‘severe’).

Question: 

Q.1 Which city from India topped in IQAir Air Quality Index?
a. Kolkata
b. Mumbai
c. Delhi
d. Lucknow